


You're The Salt In My Caramel Ice-Cream

by maeinfin



Series: Salted Caramel Ice-Cream [1]
Category: Doctor Who, Doctor Who & Related Fandoms, Doctor Who (2005)
Genre: Angst, Angst and Humor, Biting, Blow Jobs, Consensual Violence, Cunnilingus, Dark, F/M, Face-Sitting, Fluff, Hair-pulling, Hurt/Comfort, Identity Porn, Idiots in Love, Jealousy, Miscommunication, Oral Sex, Porn With Plot, Porn with Feelings, Rough Sex, Secret Identity, Smut, Spanking, Vaginal Sex
Language: English
Status: Completed
Published: 2020-03-29
Updated: 2020-07-07
Packaged: 2021-03-01 02:20:43
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 9
Words: 24,713
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23367595
Author URL: https://archiveofourown.org/users/maeinfin/pseuds/maeinfin
Summary: Crossing your own timeline was dangerous and ordinarily, the Doctor knew better than to risk it... but this was different. At least, that’s what she told herself, as she waited on the pavement opposite O’s flat. It was 6pm on a mild spring afternoon and surely, a little glimpse of O from afar wouldn’t hurt...Takes place somewhere between Spyfall and Ascension of the Cybermen/The Timeless Child for the Doctor. Much earlier for the Master who is still pretending to be O and the Doctor who has to play along.
Relationships: The Doctor/The Master (Doctor Who), Thirteenth Doctor/O, Thirteenth Doctor/The Master (Dhawan)
Series: Salted Caramel Ice-Cream [1]
Series URL: https://archiveofourown.org/series/1851370
Comments: 286
Kudos: 275





	1. Doctor's POV

**Author's Note:**

> Hello! This is my first ever fanfic and a real labour of love. I hope you enjoy reading as much as I enjoyed writing. Please leave a comment if you can.

Crossing your own timeline was dangerous and ordinarily, the Doctor knew better than to risk it... but _this is different._ At least, that’s what she told herself, as she waited on the pavement opposite O’s flat. It was 6pm on a mild spring afternoon and surely, a little glimpse of O from afar wouldn’t hurt.

In linear time, it’d been two Earth years after she’d first met O in MI6 and a year before she and the fam would meet O in Australia. By the Doctor’s calculations, whatever had happened to drive the Master to destroy Gallifrey must’ve happened to him by now. She wasn’t foolish enough to come here and ask him outright. She wasn’t even going to speak to him. She was just going to wait for O to return from work and watch from a distance. _After all,_ she reasoned, _what choice do I have?_

The Master has disappeared without a trace after the Kasavin had taken him. She’d played back the holo message a hundred times, scanned for his signal a thousand times, but still there was nothing. No sign of the Master, no clue why he’d decimated Gallifrey and no idea what the Timeless Child could be. So the Doctor had no other option but to hack into MI6’s personnel files. The Master may be good at disguises but in his own space, when he thought no-one was watching? _O will give something away, surely. And it’s harmless._

She was just going to hide here, tucked neatly out of sight behind a parked ice-cream van and wait. O wouldn’t see her and he certainly wouldn’t even speak to her.

“Doctor?”

 _Oops._ The Doctor dragged her eyes from O’s deserted front doorstep to the man himself who was vibrating excitedly next to her, a mere ten inches from where she was hunched behind the front wheel of the ice-cream van. Even the birds seemed be holding their breath.

“It’s you, isn’t it?” O’s gentle brown eyes were staring down at her, wide with warmth and the Doctor wasn’t prepared for this at all. This wasn’t what she’d pictured. Even O himself didn’t look like she’d pictured. Instead of the standard MI6 suit he’d been wearing the first time she’d met him, O stood before her now in plain jeans and a dark grey cashmere sweater.

 _Neat but nerdy,_ thought the Doctor numbly to herself. The Master was always such a method actor when it came to his disguises. He’d never have worn an outfit like this on a normal day, let alone a day when he was on a murder spree. He always liked to dress up for the occasion. Still, it was odd that he wouldn’t have dressed O properly...

“You haven’t been at work!”, the Doctor sprang up onto her feet, “Where’ve you been? Cos I’ve been waiting for you.” She trailed off lamely, belatedly remembering to _shut up_ and _stop blabbering_ and _he can’t know you know he’s the Master_ and _where’s Missy, when’s Missy? Why did you leave me?_

“It’s Sunday,” O’s smile was soft, “And it’s March so it’s quiet. Alien incursions tend to take place in winter, usually over the Christmas periods. That’s what I’ve noticed anyway, not that anyone listens to me... But still, even data analysts get weekends. I went food shopping.” He held up a tote bag bulging with groceries.

“Oh.”

“That’s me!” he beamed.

“Yes, it is,” the Doctor smiled back weakly, “Actually, I can’t stop. Lots of do, planets to save, left my fam on a volcano actually, should really get back before it erupts. You know how it is.”

“Wait! Didn’t you tell me you had a time machine? You sent me a picture,” O pulled out his phone and tapped it rapidly before waving it at her triumphantly. Looking out from the screen was the Doctor’s previous self posing with his guitar in front of the TARDIS. It was a good photo. His legs went on for miles, topped off with those eyebrows. _Did Missy take that picture? Was Missy before or after you? I thought you were my friend._

“That’s your TARDIS? So by my calculations, that means you can leave later and still be on time... isn’t that right, Doctor?” O looked smug. An ordinary human level of smugness, no maniacal Time Lord in sight. “Fancy a cuppa? You can tell me why you were spying on me. Instead of texting me.”

The Doctor could almost see time bending itself in a world-collapsing paradox around the box of Yorkshire Tea that poked out of O’s tote bag. She obviously looked suspicious. Behind O’s welcoming, easy-going expression sat the Master’s wariness at her sudden appearance. If she ran off now, he’d only think something was up and then she really would’ve messed up their timelines. _One cup of tea couldn’t hurt?_ Besides, she’d come for clues. She needed to know about the Timeless Child and if the Master wouldn’t tell her outright, maybe something in O’s demeanour would, now that she knew what she was looking for. Sort of knew what she looking for.

“Come on then!” She didn’t look back to see if the Master was following. She knew he would be.

_________________________________________________________

From the outside, O’s home was a perfectly ordinary ground floor flat in a converted Victorian townhouse. Inside, it was exactly the same; furnished and decorated exactly the way you’d expect a human male on a modest government salary to be living.

While O headed straight to the kitchen, the Doctor lingered in the living room, trying to look inconspicuous while cataloging everything in sight. _So O’s not always messy!_ The Doctor hummed to herself. The living room was much tidier than the shack in the outback. _Still a hoarder though._ She could hear the kettle starting to whistle and the dull thump of cupboard doors and mugs as O busied himself in the kitchen. His complete set of Fortean Times was lined up neatly on the bookcase that spanned the length of the room.

Disappointingly, it all looked very O and not at all like the Master had left any devious plans lying around. _How do you even do this? You love to gloat and show off. Doesn’t it hurt to pretend for so long? Was Missy pretending all along?_ Suddenly, the sensation of being watched threw the Doctor out of her self-pity. Breathing slowly, she honed in on the feeling, then stretching up to the uppermost bookshelf, the Doctor pulled down... a tiny figurine.

“What do you think?” O’s movements had been as soft as his voice. She hadn’t heard him leave the kitchen but here he was beside the Doctor, holding two steaming hot mugs in one hand. He reached over the Doctor’s head with his free hand, “I made them myself with a 3D printer. My tiny alien dolls.”

In his palm lay an miniature Cyberman, a Vinvocci and a variety of humanoid figures.

“They’re very... lifelike,” the Doctor said, suppressing a tremor at the memory of the Master waving his TCE around in the Adelaide Gallery. _The anger, the rage._ She prodded her mental shields to check they were still in place. There was no sign of the Master poking around her head. Nothing. _Good, just my own feelings then._

“You can keep that one if you like, Doctor,” O nodded at the tiny Judoon in her hand “I can always make another.”

“No thanks!” She gasped, thrusting it at him, “I’ve met enough of them in my lifetimes. You keep it, why trouble yourself getting another?”

“It wouldn’t be any trouble, Doctor, I quite enjoy making them,” O smiled serenely.

 _Of course you do._ The Doctor suppressed an eyeroll.

O lined the figures back up on the bookshelf, before handing her one of the mugs, “I do hope two sugars is alright? You strike me as the sort who’d have a sweet tooth.”

“What gave you that idea?” _As if you don’t know exactly how I take my tea, you infuriating gloating_ \- the Doctor sipped her tea. It was exactly how she liked it - _thoughtful lunatic._

“I did just find you hiding behind an ice-cream van. Is that something aliens do a lot? Or just you?” O settled into the large, brown leather sofa that dominated his living room. He gestured at the space next to him and waited for the Doctor to relax into her seat before he turned to look at her.

“Do you spy on all your old friends?” The Master’s eyes glittered at her sharply. _Uh oh._


	2. Master's POV

The Master had realised she was waiting for him before he’d even turned the corner onto O’s road. He had always been able to spot the Doctor, whatever face she wore, whatever body she had, however long it had been. Sometimes it was the scent of wet, red grass that caught him and sometimes it was a certain heady rush of blind ego that made the air take on a sweet, custardy tang. The Doctor’s preaching was always so unbearably saccharine, whichever form she took.

He’d been momentarily perturbed to see her, especially so close to his TARDIS. He’d picked an ice cream van for his own amusement. He couldn’t afford to cause too much chaos while disguised as O and he also wanted the TARDIS nearby. Seeing human children’s faces light up when they saw it and then fall in disappointment when they realised no-one was in; that was merely a harmless bonus. _Really, the Doctor would be pleased, if she was ever smart enough to see what's in front of her._ She didn’t know O that well and she certainly didn’t know the Master was alive in front of her, so _let's see how she feels about the fact she’s upset one of her precious humans._

He’d been careful with O. They’d texted a little; O had admired her stupid bow-tie-and-fez combo. Her last incarnation hadn’t been particularly chatty but the Master could forgive that, seeing as Missy had held most of the Doctor’s attention. He’d made O a bit clever, sure, but only by human standards. Just enough to pique her interest with a dash of scientific brilliance to keep her coming back. She was always so easy to predict when it came to her humans, _so why not have a little fun?_

“Do you spy on all your old friends?”

The Doctor froze deliciously. He let O’s affable smile slide away; only his own rage remained, twisting his mouth into a smirk. _Surprised your pet would bite? But Doctor, you always push and push until they break._

“I didn’t expect this, Doctor. I trusted you,” O’s tone was hard but his mouth softened into a droop, “I know they mock me. For believing in aliens, for believing in you. Have I done something wrong?”

O’s eyes were so, so wide - the Master could feel them watering, he wanted them to water. _Would that be too much? Don’t get carried away._ The Doctor’s face was perfect, cringing and twisting in chagrin. He could watch her suffer for days... if only it was for something that deserved her shame. _If only you knew what I’d done to Gallifrey, what they’d done to us. If only you knew the pain in my hearts._

“No!” She blurted out, “You’re right, I shouldn’t be here. I got greedy, you see. I wanted to see you.”

The Master didn’t have to feign O’s surprise, “What do you mean?” _This better be interesting._

The Doctor downed her tea with swift nervous gulps.

“I was worried about you. MI6 are too daft to see what’s in front of them.” _Oh, love, the irony!_ It was far too early to reveal himself - his plans for Earth domination were still forming - but for a brief second, he pictured how her face would contort in horror if her best enemy appeared now. _Too daft to see what’s in front of them. How right you are, my dear Doctor._

“I got the sense they weren’t taking you seriously,” she continued, “Did you know they’ve closed UNIT? I’ve always thought they were idiots. I mean, I knew they were when they made me President. Sorry. I’m doing it again, aren’t I? Bit of a rambler, me. Didn’t used to be! My last self barely texted you back and now, here I am, doing a welfare check! Must be getting soft.”

The Master kept his face carefully blank. _So tedious._ Of course she would have come all this way to check on her pet’s feelings... As if there weren’t more pressing things for the Doctor to concern herself with. _When’s the last time you went home? I razed it to the ground for you and you don’t even appreciate it. You don’t even know who you are._

The Doctor had paused, waiting for O respond and when he didn’t, she ploughed on, “I’m sorry I was spying on you. You’re right, I should’ve sent a text.”

The Master sighed inwardly. _Come on, love, you’re not even trying. O’s not one of your silly Earth girls. Give him some effort._

“Can you forgive me?” the Doctor kept going, “I’m just a bit awkward in this body. Still getting used to me.”

That caught his attention. _What else about this body are you still getting used to?_ He remembered exactly how awkward the Doctor had been in her last body. How Missy had enjoyed coaxing him out and then breaking him in. He let O’s eyes drift over the Doctor’s new face. Time Lords didn’t concern themselves with primitive notions of gender and until this moment, he hadn’t really thought about the fact that the Doctor was a woman now. _This is going to be fun._

“It’s alright, Doctor. I do forgive you. On one condition?” O’s eyes were kind again. The Doctor’s anxiety shed visibly off her shoulders and her eyes crinkled with a warmth that matched her smile.

“Anything!” She beamed.

Making sure his telepathic shields were iron-clad, the Master met the Doctor’s thrillingly open gaze; she’d never accept this if she knew he was really was. Slowly, he looked down at the space between them. O’s open palm hovered in the air before her.

“Take my hand.”


	3. Doctor’s POV

“Take my hand,” O’s open palm hovered in the air before her.

The Doctor stared at the hand between them. Those were words she hadn’t heard from the Master since they were boys at the Academy. She’d dash off on a whim and he’d stumble behind her, calling at her to slow down and take his hand. He’d never been good at sprinting. He was always the last one in every race. _Hang on, that’s what O said on Barton’s aeroplane. That’s when I caught you out... So it’s not all a disguise, the real you still slips through!_

Checking her mental barriers were in place, she reached out to press her palm into O’s. _Something you say will reveal why you destroyed our home... and I’ll know it when you do._

O’s hand felt familiar in hers but before she could think too hard on why there was suddenly a warm tingle rushing through her, he'd pulled her to her feet and tugged her towards a doorway that led further into the flat.

“Where are we going?” the Doctor tried to sound casual as O led her down an ordinary looking corridor. At the end, she could see a bedroom. _Surely O doesn’t mean that kind of apology?_ The Master wasn’t above sexual punishments - that’d been the Doctor’s favourite kind of fun when they were fumbling 80 year olds at the Academy. The Master had made sure to remind her of those times during The-Year-That-Never-Was, toying with her guilt and love and pain and desire whenever he felt like it. _But O’s too sweet for that. I bet he even snuggles._

The Doctor shoved that bizarre thought out of her mind, checking her mental shields again, as she let O lead her past a double bed to the far end of the bedroom.

“Here we are,” O pulled back a dark purple drape that hid a wall of computer screens arranged in a jumble on a long desk. It was the same kit that Graham would call ‘paranoid’ in a year’s time in O’s shack in the outback.

“Impressive,” she hummed, briefly trying to look impressed before giving up, “Sorry, how does this mean I’m forgiven?”

O chuckled, “This is my secret plan, Doctor, and you’re forgiven if you can keep my confidence.”

She looked back at the equipment before them. Most of the screens were turned off or monitoring frequencies that showed nothing of interest. Whatever the Master’s actual secret plans were, they wouldn’t be on display here. For one thing, O’s ivory white bedspread and the soft furnishings weren’t the Master’s usual backdrop. He’ll definitely have something more spectacular brewing.

She looked back at O, “Go on then, I love a good plan, well, mine are more like works-in-progress, to be honest, but I’m sure yours is a proper plan.”

O let the drape fall back to block the computers from view, “The system is all mine, not MI6’s. I know what they say about me, Doctor. They call me Horizon Watcher but they might as well say I’m a Flat-Earther. I’m not as daft as they think. Should anything happen and MI6 disregard my reports as they always do, I’m prepared and I have a place to go. Not even C will know where I am.”

“An escape plan. For when they realise their imaginary monsters are real,” the Doctor murmured.

“I knew you’d understand,” O looked so lost that she almost believed him; she almost wanted to reach out and reassure him that yes, aliens do exist and she was right here.. when he squeezed her hand. With a jolt, she realised they’d been holding hands since he’d led her from the living room. _Isn’t this weird for humans? Aren’t they a bit touchy about touching? Does it count if the Master’s only pretending to be human? Maybe he thinks that humans think Time Lords think humans hold hands all the time. Wait-_

“Umpf,” the Doctor gasped. O’s lips were on hers, his fingers threading through hers and his other hand resting on her hip. The kiss was soft and chaste.

“Is this okay?” O lifted his hand from the Doctor’s hip to her cheek, pushing a loose blonde strand behind her ear. His eyes were wide and wondrous and so needy. “It’s just so nice you’re here, to have you as my friend.”

The Doctor’s hearts flip-flopped. Her lips didn’t seem able to move to say aloud, _no, it’s not okay. No, you’re only pretending. No, I don’t care about clever, fake O because he isn’t real, you aren't-_

“I’ll always be your friend,” she kissed him back.

__________________________________________

Somehow, they were lying on the bed, facing each other. The Doctor wasn’t quite sure how that’d happened or when her coat had been discarded on the floor. O was still kissing her, his movements still soft but nowhere near as chaste as before. A dim voice in one of her brains was telling her that this was a terrible idea. Her other brain was helpfully pointing out that sex was probably less paradox-inducing than actual conversation.

If she hadn’t already known that O was the Master, she might’ve realised now. _You always kiss the same._ Still, although the technique was familiar, it wasn’t quite like being kissed by Saxon, who had literally been sharper, using his teeth to bite and nip until the Doctor’s lips bled. And it wasn’t quite like kissing Missy. She had either teased or devoured. The Doctor shivered. This time, O was gentle, moving slower and more cautiously, seeking permission in a way that was unfamiliar. _He really has no idea I know who he is._

O’s hand slid downwards to rest on the band of her blue trousers and toy with the hem of her t-shirt. His fingers were tracing her hip through her t-shirt, hesitant to touch her bare skin without some encouragement.

“Take this off,” the Doctor tugged at O’s cashmere sweater. The words felt awkward on her tongue. River had always been the one giving the commands, the Master simply took whatever pleased him, and everyone between tended to be eager to impress - Like O was now; smoothly removing his sweater, then pulling her t-shirt over her head and deftly flicking off her sports bra with one hand.

“Oh, nicely done!” the Doctor gasped, genuinely surprised. “I never got the hang of that, even when I was a man!”

O eased her back down onto the bed and kissed his way slowly down her neck, palming her breasts gently with his hands, “Is that so? Well, I quite like you as a woman now.”

“Better than before? I had longer legs before,” the Doctor sighed as O took a nipple into his mouth. His movements were smooth and confident, all the Master’s self-assurance with none of the bite.

“This is definitely an upgrade. I’d always consider being a woman an upgrade,” O murmured, suckling gently on first one nipple and then kissing his way to the other.

A vision of the Master’s past self flashed vividly in the Doctor’s mind; Missy laying on the bed beside O, digging her fingernails into the trail of O’s gentle kisses, twisting the Doctor’s nipples in a painful grip just as O’s warm, soft tongue lapped around them. For a split second, the image seemed so real that the Doctor felt herself flushing; two Masters were a terrible idea at the worst of times, but at the best of times... _Focus. You’re risking a paradox if he hears you._

Reassuring herself that her telepathic barriers were still intact, the Doctor reached down to O’s broad shoulders and pulled him up for another kiss. Underneath her palms, his chest hair was soft and thick. _How do you keep getting such attractive bodies?_ This time, it was her own hands that were reaching down to his waist, first to loosen his belt and then to pull his body flush against hers. She could feel his erection pressing into her, despite the layers of clothing between them.

Steadying himself above her, with a forearm on either side of the Doctor’s head, O’s eyes seemed to cocoon her. It felt strangely overwhelming and she let her gaze drop to his lips instead. He was smiling at her bashfully as he circled his hips against her. She could feel her own arousal flaring up in response, her body remembering how Saxon used to do this when he kept her on the Valiant. When he tired of burning whole cities, he’d de-age her and hold her while she cried. _Heat and guilt and lust and shame._ It always ended like this, with the Master on top of her, kissing her until she forgot everything he’d done. _So change it._

In one swift move, the Doctor flipped them over so O was underneath her. She tugged his jeans off and smirked when O grunted in surprise. She leaned in to kiss his neck and suck gently on an earlobe. _I know what you like and you’re not getting it._ Her teeth grazed back along his neck but instead of biting down as she knew the Master would have liked, she teased her way downwards, along O’s collarbone, circling his nipples and onwards down his navel.

O’s boxers were a plain, dark blue cotton but they couldn’t hide the erection that was straining to escape or the patch of pre-cum leaking through. Slowly, the Doctor nuzzled his cock through the cloth, letting her tongue dart out to toy with the head. Soon, the front of his boxers were drenched in her saliva and his pre-cum. O’s breathing was shallow and when she glanced up at his, his pupils were fully dilated.

“You’re such a tease,” O sighed, as he reached down to trace his hand over her lips which were still pressed against his clothed erection.

She smiled and sucked his fingers into her mouth in response, before tugging at the waistband of his boxers with her free hands. As he kicked them off, the Doctor couldn’t help but sit upright and consider the Master’s new body properly. She hadn’t looked at O like this before all that had happened with Barton and the Kasavin, but as always, the Master’s big reveal had changed everything. Now, she couldn’t take her eyes off him. _You really are very symmetrical._

“Have I caught your attention?” O’s smile was playful.

“Maybe.” _Always._ Glancing back down at his cock which was now bobbing freely between them, the Doctor finally lost patience. Pushing O’s hips firmly down into the mattress, she leaned in to graze her nose against the tip of his cock. As she blew against it, pre-cum beaded out, forming a sticky thin line that connected them together. Fighting back a sudden urge to giggle, she wrapped her lips around his cock and began to suck.

At first, her movements were slow but deliberate. O was looking down at her with awe as she let her tongue dance against his silky skin. His cock was thicker than Saxon’s, but about the same length. She reached out to caress his balls in one hand, then gently drew first one and then the other into her mouth. As she licked and sucked on his sensitive skin, O’s sighs sent vibrations through her body straight to the heat pooling between her thighs. _Isn’t this nice without the pain for once? You should let me do this more often. Without O._

As she moved back to his cock, licking slowly from base to tip and back again, she could feel O’s hands hovering over her head, too polite to touch. Instead, he gathered the loose strands of her hair and scraped them back behind her ears before stroking her cheek softly.

“You feel incredible,” O groaned. Pleased at the compliment, the Doctor glanced up at his face and froze. Despite his throbbing erection and the positive feedback, O looked far too composed for someone who claimed to be feeling incredible. His eyes were fixed steadily on hers with one hand still caressing her cheek. She was reminded sharply of her former pinstriped body entangled with Saxon, but this time, in her mind’s eye their positions were reversed. Her past self was gawping down in awe at the Master lavishing attention on a cock she no longer possessed. _Do I really look that lovesick. No wonder the Master’s always scoffing. But why would I remember looking up at my own face?_

The Doctor gasped and O’s cock fell out of her mouth with a lewd pop. The lust-spiked visuals weren’t her own memories; they were the Master’s. _Is he in my head? Does O know I know he’s not O?_ Fighting down her panic, the Doctor ran her hands over O’s thighs, leaning close to hide her face from him as she licked wetly around the base of his shaft. _Telepathic barriers still up and besides, he’s power-crazy not actual crazy. He wouldn’t risk contact when he’s playing human. Oh... he’s projecting everywhere! The whole street could probably hear him if they weren’t psi-null._

She glared up at O but his eyes were closed. _I’m not risking a paradox so you can get off to our memories._ O looked almost serene on the bed, as if he were enjoying a warm bath instead of a hot tongue caressing him. _Fine, we’ll do this your way, Master. You don’t get my attention if you’re not going to appreciate it._

She grasped his cock with both hands in a tight grip and squeezed fiercely. His erection twitched at the sudden pressure and O’s eyes shot wide open. As the Doctor grazed her teeth over his shaft, O winced as if in pain but his erection throbbed hotly in her hands. Biting down slightly as she went, she pressed herself closer until he was deep inside her throat. Her tongue moved in jerky, rough circles on the underside of his cock while her incisors were a sharp, unsteady pressure around him. His breath was a series of uneven hisses, each in tense response to her teeth pressing threateningly against him

The next time she glanced up, O’s hair was in disarray. His head was thrown back against the pillow, a thin sheen of sweat on his face and he almost looked flushed. _New body, same tricks_. Unable to smirk with her mouth full, she settled for a particularly sharp bite and was rewarded with a hiss and the Master’s hands buried in her hair. His fingers twisted and tugged at her roots. The pain was hot and comforting, sending sparks from her scalp through to her jaw as she alternately bit and licked her way around his shaft.

Even though she couldn’t see his expression clearly enough to guess what he was thinking, the projections had ebbed and she could feel the heat radiating off his skin. _Lust, fear, distrust. Or is that me?_ His hips were jerking minutely, but he couldn’t thrust deeper into her mouth. The Doctor’s weight was on her elbows, which were in turn digging sharply into his thighs. One hand pressed hard into his navel, pinning O against the mattress. She could tell he was close. The hands wrapped in her hair has lost all pretence of gentlemanly hesitance and she couldn’t have pulled off his cock even if she’d wanted to. He was buried deeper in her throat than he’d been in almost a millennia. _That can’t be true. Missy had those toys -_

Suddenly, the grip in her hair changed. Instead of pressing her closer, he seemed to be tugging her away.

“I’m going to-,” O’s face was desperate and considerate at the same time. Knocking his hands away impatiently, the Doctor swallowed him again and scraped her fingernails roughly against his balls. The tremors in his thighs increased. Pulling back his foreskin, she sucked hard and in one deft move, dragged her bottom teeth sharply against the exposed oversensitive skin. He came with a shout, exploding hot and sweet into her mouth before slumping back bonelessly.

Finding herself trembling all over, the Doctor lay her head on his thigh and let her own weight drop down onto him. The tension had drained out of O’s body and he was a soft, sweaty log beneath her. She could feel the wetness of her own arousal between her legs but it felt cool now instead of fiery.

Suddenly exhausted, she placed her hand over O’s erection, marvelling at it softening in her hand. _Mine used to do that._ Her petting was interrupted by O tugging at her hand, pulling her for a deep, wet kiss. _You’re so self-obsessed. I bet you love how you taste in this body. I do._

“That was perfect,” O breathed, “How did you know I’d like that?” His hand was caressing her cheek again, but this time his thumb pressed gently on her bottom teeth.

 _Because we’ve been hurting each other for two millennia._ “Human biology’s quite similar to Time Lords,” she mumbled into the space between his nipples. _If I still had chest hair, would it be blonde?_

O frowned, “So that was a Time Lord thing?”

“You could call it a Doctor thing,” she hummed. _Only you would manipulate me with a personalised sex tape, then be suspicious when you get exactly what you want._

“Interesting. Are there any other Doctor things I should know about?” O’s hands were sliding suggestively down her back. She’d lost her trousers at some point and his hands settled questioningly on her hips, his index fingers stroking the elastic on her black, cotton knickers.

“Plenty,” she leaned up to kiss him again as his hands slipped under her waistband to grasp each cheek. He pulled her closer, manoeuvring a muscular thigh between her legs. She sighed as she rocked against him lazily. Her hot lust had vanished and in its place was a different sense of longing but she was too tired to identify it properly. Her eyelids felt heavy and she couldn’t remember the last time she’d felt so relaxed. _Maybe that time we watched Frozen and you had learnt all the songs?_

“Sleep. You can show me later,” murmured O. His hands were higher up now, the pads of his fingers pressing gently into the muscles on either side of her spine. They felt like warm suns, burning out all the aches Missy had left.

The Doctor nuzzled deeper into his chest. As she felt herself start to drift off, she could feel O’s hand tracing circles on lower back. It almost felt like Gallifreyan but before she could focus on the path he was drawing, she was fast asleep.


	4. Master's POV

**Notes for the Chapter:**

> A gentle reminder that the Doctor knows exactly who O is and therefore, knows exactly what she's doing... but this is written from the Master's POV.

While he waited for the Doctor to wake, the Master traced _hate, hate, hate_ in large, looping Gallifreyan over her bare back. Her skin was warm under his touch but he pictured his finger as an even hotter ember, burning red circles into soft flesh. Each swoop of his hand was a promise. _You’ll never hate anyone as much as you’ll hate me._

He had calculated everything with the Doctor in mind. _All the best plans have purpose. Especially those designed for best enemies._ He certainly wasn’t biding his time in an insignificant government job for his own amusement. _I’ve got better things to do than document your pitiful mishaps on Earth._ He could conquer any civilised planet in the universe if he wanted to and here he was, aiming for nothing more than this wretched dump, just because she liked it. _It’s a literal sacrifice._

When the Doctor finally started to rouse, his finger had twirled _hate_ around her hip for the two thousandth and something’th time. One for every year of their lives. _That she knows of._ He pushed down his flaring rage, wary of the fact that even with his telepathic brilliance, there was always a chance his anger might bleed through. Flashing memories at her mind when she was spaced out on sex hormones was one thing but if she knew who O really was, she wouldn’t have kissed him back and that would’ve ruined his fun.

While she’d slept, the Master had reviewed everything O had said and done until he was satisfied he still had her fooled. _She never recognises me. She never even looks._ And if she’d had the slightest suspicious of O, she’d certainly never have fallen asleep on him like this. Her body was draped over every inch of his, nestled in turn under the huge cloud-like duvet he’d pulled over them. Even her toes were wriggling against his bare feet.

“I know you’re awake,” O’s toes curled back against hers. _I could make you love him. More than you’ve ever loved those Earth girls._

The Doctor snuggled into his chest in response, “I like it here. I don’t want to move.”

“So don’t,” O’s voice was a warm caress, “Stay the night.”

The Master regretted the invitation immediately; the Doctor radiated instant tension in O’s arms. _Always running and never mind who you leave behind. You want me to change but you never do._ Before she could ramble out some paltry rejection that would spoil O’s seduction, the Master tightened his grip around her and rolled them both over. His lips were on hers, kissing her into silence until she softened back into the bed.

Slowly - because O was the gentle type and because the Master always knew when a plan required patience - he feathered kisses from her lips down to her neck. There, he sucked gently, feeling her pulse slow and the last edge of tension ebb away. The temptation to bite down was high, although O wouldn’t do that. _But I can still bruise you._

“S’pose I could stay a little longer,” she sighed, her eyes fluttering closed.

Pleased - _this is going to be so much fun_ \- the Master pursed his mouth even tighter around the pulse point in her neck and let O’s hands drift downwards to her bare nipples. He rolled an erect bud between a thumb and forefinger, enjoying the way she quivered uncertainly. When he’d been Missy, it had taken him a while to discover how his new breasts responded and even longer to work out what he’d liked.

“How does this compare to when you were a man?” he asked as he flicked the nub back and forth with his fingernail. It wouldn’t hurt but he could tell from her face that she wasn’t convinced.

“Different. Nice. Odd,” the Doctor’s hands were on her own nipples now, thumbs brushing under his own to give herself a curious pinch, “I always thought these would be more... reactive?”

“Maybe I can help,” he swept her hands away and wrapped his mouth about the nipple closest to him. _Everything you think you know, everything you will know... will be because of me._ His tongue swirled around her areola, wet and fierce, exactly how Missy had liked it but that Doctor looked down at him blankly, her nose scrunched up in concentration.

“It’s ticklish. I don’t think this body is very sensit-” she broke off with a gasp, ”Do that again!”

The Master had the tip of her nipple between his teeth and was rolling his lower jaw from side to side. He’d detested being on the receiving end of this move during his last regeneration but wasn’t surprised the Doctor would like it. _You always love everything I hate. You always have to be so different._

As he gave her other nipple the same treatment, occasionally yanking a little too harshly for his own amusement, his hands glided smoothly down until they landed on her hips and then shifted inwards, over her knickers. Circling his fingers over the thin material, he traced the outline of her labia, relishing the way her thighs parted keenly underneath him. _I’ll make you beg until you break._

Giving her nipples a final bite, he glanced up at the Doctor. Her pupils were blown and her gaze was fixed on his mouth. _How far will you let O go?_ He let his tongue trace his lower lip, relishing the way her eyes followed as though hypnotised.

“Doctor, when you said you’re still getting used to this body, did you mean....?” he let O trail off shyly, but his fingers were still moving in firm, confident circles over her knickers.

The Doctor looked perplexed for a second before she grinned, “Yup. I’m brand new! I mean, I’ve had a go on my own but I haven’t-,” she broke off with a whimper.

O’s hand had shifted further downwards and he was pressing the tips of his fingers into the space between her thighs. He could feel her body responding through the damp material, her entrance grasping futilely as he pushed against the soaked cotton.

“You haven’t...?” he knew O’s eyes were shining with unbridled excitement but he didn’t care. _Come on, Doctor, say it, come on._ Instead of answering, she pulled him up towards her for a long, deep kiss. When the Doctor finally drew away, her hands were furnaces on his cheeks and her eyes were so warm, _so trusting, so blind._

“Fancy being my first?” she breathed.

The Master’s smile was entirely his own, “I really, really would.”

________________________________________________________

O was going to be the ideal lover, gentle and giving in every way. _Your first time in this body with your dear human. This is going to be spectacular._ Initially, the Master had pressed himself against her, intending to embrace her softly the way he knew O wanted to - _it’ll be so perfect that your hearts will crack in two_ \- but he’d felt his own heartbeat accelerating into a maddening, treacherous rhythm. He had tried to ignore it but paranoia quickly won out and he’d shimmied downwards, fluttering exhilarated lips along the Doctor’s skin, until he had a hand on each knee and was sucking a hot bruise onto an inner thigh.

“Yes,” she spread her knees apart, trying to coax him higher, but he ignored her in favour of biting firmly until there was a row of tooth marks lining a path along both her thighs. He’d been careful not to break her skin and O had dropped soothing kisses over each blossoming red line. _Beautiful._

When he finally reached the space where the two rows of bite marks met, the Doctor was panting hotly and squirming beneath him. _Always so impatient._ The Master paused to press his cheek against her, breathing in the hot scent of her arousal. Satisfied that he had made her wait long enough, he puffed momentarily over her covered clit with a warm teasing breath before moving lower to mouth wetly at her labia. Through the thin cloth, he could feel her lips were already swollen in anticipation.

He pulled at her knickers gently, just low enough for her to kick off. He could feel his own curiosity pounding in his brains _. Your first female body since we were young. The only one you remember._ She was fuller than Missy had been but less symmetrical. One of her lips puffed out, enlarged with arousal, the other one tucked thinly alongside. Unwilling to wait any longer - _you have no idea what’s coming_ \- he sucked the larger lip into his mouth, letting his tongue probe against her sensitive skin in rough, sweeping motions.

He was so engrossed in her soft sighs and how they rose and fell, that he jumped when her fingers entangled suddenly in his hair. His bottom teeth scraped along her flesh, eliciting a strangled gasp from above. He was about to rush O into a soft, grovelling apology when he caught a glimmer in her eye. _This body likes... danger? Pain? Fear?_ Tugging her swollen lip back into his mouth, he rolled it experimentally between his teeth, not quite biting down but firm enough to be a steady, threatening grip. Her response was a low, quivering moan as her head dropped back against the pillow. _Interesting._

Her hands were twisted desperately into his hair when he eventually moved to her other, thinner lip. This time, she flinched when he pulled at her with his teeth so he opted instead for a softer, wetter, sucking motion. He let O’s eyes drift closed, focusing only on how the Doctor was squirming hotly underneath his tongue.

Growing impatient, wanting her to beg, wanting to see her break apart, he moved his mouth to the space between her folds, pushing his tongue into the sensitive inner skin. He wiggled the tip of his tongue experimentally, brushing side-to-side, up-and-down and even diagonally until she bucked up against him with a gasp.

“Oh god,” her hands were curled into the bedsheets beside her. She’d drawn her knees up and her feet were resting on O’s broad shoulders. From this position, seeing her splayed open so invitingly, the Master was tempted to push himself up and into her. _No, wait for your moment._

Inhaling deeply, against the rush of adrenaline and his own keen arousal, he fixed his eyes on her swollen clitoris. The Doctor had said something fun to Missy when she’d been a grumpy, blind Scotsman. _You told me your memories were so much worse in the dark._ The Master pressed a soft, joyful kiss on the Doctor’s clit. _This one will be so much more in the light._

As he worked the tip of his tongue around her clit in steady circles, he closed his eyes and let the sound of her breath deteriorating into shaky, uneven pants wash over him. Nudging her legs so that her ankles locked behind his head. he pulsed the flat of his tongue directly against her clit. Her thighs were trembling under his palms and his own excitement was mounting. He could feel she was close - _Come on, Doctor, come on, come on_ \- but then, her hips started to rock a jerky, frustrated beat against his mouth, before she stilled with a huff.

“It’s so intense, but I can’t-” the Doctor whimpered. Her nose was scrunched up in that irritating confused expression, “There’s something blocking me.”

The urge to scream was overwhelming but the Master settled for sinking his teeth savagely into the crook of the Doctor’s neck. Once her skin had split, and the tang of metal overrode the taste of her arousal on his tongue, the flare of his rage had abated into an ebb he could control again.

“That’s okay,” O’s tone was reassuring as the Master planted soft, bloody kisses along her jaw. The red stains his lips left behind soothed him further. _So beautiful._

“My regeneration must’ve gone wrong. I’ve seen that happen before. He was always hungry.” her eyes flickering between confused and panicked, as if she wasn’t yet sure which gut feeling to follow. The Master buried his face back in her neck to hide his grimace. _That was a resurrection ritual, not a regeneration. You have no appreciation for brilliance._

He huffed and turned his mind back to her problem. He’d had the same issue when he was Missy. He also had the answer. _What would you be without me, Doctor? No-one understands you like I do._

“I’ve got a plan B. Sit on my face,” O purred. He rolled on his back and pulled at her hip until she obeyed. This was something else Missy had enjoyed. _What better way to show the Doctor who’s in charge?_ The Master frowned as the Doctor’s knees settled by his face. _On reflection, that’s always me. Position is irrelevant._

“Why are you pouting?” the Doctor was staring down at him with that stupid, puzzled expression again. He almost snarled but caught himself and stretched his lips wider and higher until O landed on a toothy grin. She didn’t look any more reassured.

“Come here,” O said, tugging her down towards his mouth. Judging by the way she instinctively softened above him as his tongue swiped along her labia, she’d already forgotten her train of thought. Her arms were resting on the headboard before her and she started to rock against his mouth, guided by his hands on her hips. Soon, her eyes had fluttered shut and the only sound she was making was quiet, hungry gasps.

“Do you feel that?” he asked, muffled by the grip of her thighs clamped around his face.

“What? Do I feel that?” her incredulous laugh broke off into an unsteady moan as he engulfed her labia in a hot, wet yawn. The Master began to hum in a deep, funereal monotone - _Hey Missy, you’re so fine. You’re so fine, you blow my mind_ \- until he could feel her wetness dripping over his chin. _Oh Doctor, I’m going to blow your mind_. He fought back a wild giggle.

“Picture that feeling like it’s a bright star,” he nudged her hips until she’d shifted forward just enough for him to swirl his tongue at her entrance.

“A White Point Star?” the Doctor whimpered weakly above him.

O’s reply was suitably starstruck, “I don’t know what that is, Doctor, but I imagine it’s beautiful.” _Technically that’s a diamond. Must you always be so dramatic?_ Only the Master’s tongue belied his irritation, sliding and wiggling around her entrance, but never venturing inwards. _Do you ever stop showing off your whole-of-space-and-time act to these primitive humans._ He hid his fury beneath a flurry of firm licks until she was grinding down desperately for more.

“Imagine that star,” he murmured, “First it’s small and bright. When you feel good, it gets even brighter. When you feel great, it gets bigger. Closer.” Tensing his tongue into a sharp point, he jabbed up into her. The grunt she made was infinitely satisfying.

Her eyes were closed and her head flung back. She was moving up and down in a steady, hungry motion, riding his tongue. She was so wet above him, on him but he wanted more. He pulled her closer, tighter against himself. His nose pressed against her clit and he was rewarded with another gush of her arousal flooding onto his tongue. _I’m going to destroy you._

“Forget everything. Let the light consume you.” _Or the dark. Or the madness. Or the rage. The planets we could have ruled together._ He nudged his nose harder against her clit, relishing the way she ground carelessly into his face. He’d already switched to his respiratory bypass but he’d doubted she’d notice. She was rocking back and forth, up and down, unthinkingly, selfishly. _Come on, Doctor, come on._

When she came, it was with a dreamy sigh. The Master’s eyes were wide, fixed on her open, ecstatic face before she stilled and slumped forward against the headboard. _So vulnerable, so oblivious, so much potential for pain._ His bite marks and bloody kisses shone like rubies on her skin. He wanted to sear every line into his memory.

It took her several minutes to come back to herself. He could see the exact second she registered his hand softly tapping out a drum beat on her thigh and the way her eyes widened in alarm.

“Did I hurt you? Am I heavy?” She scrambled off him so quickly that the Master couldn’t help but genuinely laugh.

“Doctor, you’re tiny,” he said as he pulled her down to lay against his side, “You could never hurt me.” _Not as much as I’ll hurt you._

“Oi! You’ve only got an inch on me,” the Doctor smiled, still soft and dazed, “My last regeneration towered over you. He would’ve towered, I mean, if you’d met him.”

 _But I had better legs and you couldn’t run in Missy’s heels. You probably still can’t._ Instead of responding, the Master rolled on top of her, dropping light kisses over her face until she started to squirm from O’s affection. Before she could wiggle away, he rocked his hips against her gently, letting his erection poke rudely against her stomach.

“Only an inch, you say,” his lips curled into a teasing smile. _Cue the bashful human lover, standing ready to capture your hearts._ A soft sigh escaped him as the Doctor wrapped her hand around O’s cock. She had a suitably cheeky look on her face. _Is that the same smile you give your pets before you fly them to a premature death?_

Her playful smile reminded him vaguely of the role-playing they’d done in the vault. _Judoon-Master arresting the Doctor, Slitheen-Master enslaving the Doctor, the Master-of-Plentitude experimenting on the Doctor._ The last memory made his skin prickle strangely so he turned his thoughts back round to the Doctor.

There’d been that time she pretended to be some skin called Cassandra. He’d tied her up and she’d squealed ‘moisturise me’ until he came on her face. _Repeatedly._ And maybe one day, he’d tell Captain Jack Harkness what his precious Doctor had done to the Face of Boe-Master. She may be terrible at disguises and a truly appalling actor but _we had some fun, didn’t we?_

His erection was rock hard now. Her hand was tugging at him, sending a warm buzz right into his hearts. He was sure O’s eyes were wider than Jupiter’s moons, as she lay before him, spreading her thighs apart and wrapping them invitingly around his waist. If he had a moral compass, he might’ve thought twice about deceiving her. _But I don’t have one._

“Are you sure you want to do this?” he made O’s tone so tender he almost believed his own hesitation. _Not._

“Please,” she pulled him closer against her. She was looking at him like O was something special. Like he mattered to her. _Since you ask so nicely..._

She was still soaking. He didn’t even need to push. As soon as the head of his cock lined up with her entrance, she seemed to draw him in. He sank inside her so effortlessly, he had to fight back a hiss of triumph. _You may have made me but I will destroy you._ He pushed O’s face into the crook of her neck, allowing himself a little hidden smirk. One day, when she realised who O was, she’d remember this moment and how considerate he’d been and her hearts would break. _It’ll be exquisite. I can’t wait. Perhaps I should tell you now._

Wrapping his arms around her in a soft embrace, he started to thrust gently. His pace was slow and indulgent. As he rocked, he contemplated the merits of unveiling himself that night and how he’d do it. _Wasn’t that masterful? Too cheesy. Did O blow your mind? Doesn’t flow. Got you? Too obtuse._

A soft sound from underneath him jolted him out of his thoughts. It was only when the Doctor let out another long, blissful moan that he realised his hips were slamming into her at the slowest, hardest pace possible. He’d been so focused on potential, terrible reveals, he’d started to thrust harder without noticing. He was definitely pounding into her far harder than a human would be but she was oblivious, judging by the glazed look in her eyes.

He grunted as he drew another hot moan out of her. She felt incredible but he wanted to draw this out. If there was one skill the Master had truly honed, it was patience. _It doesn’t matter if it takes 8 months or 80 years, this stinking planet will be mine. One day, you’ll know everything and_ \- a broken whimper from the Doctor snapped him back to the present.

Her eyes were wet with unshed tears. _No, no, no. This has to be perfect. Exquisite pleasure before glorious pain._

“Doctor? Am I hurting you?” he stilled and softened O’s voice even further, until it was tender with worry.

She shook her head but a tear escaped as she did. The Master watched as it trailed down the side of her face into her ear. It was hypnotising and far too premature.

“Tell me what’s wrong?” his concern was real. _It would be a shame to ruin a good suffering before it’s ready._ Instead of replying, she closed her eyes for so long that the Master could feel panic starting to bubble within him. When she opened them again, the tears were gone and her gaze was bright and clear.

“You’re brilliant, you are,” she was looking at him as if he wasn’t there at all, “You really are. You’re beautiful.”

It was strange how a platitude he’d heard countless times before - _that she evidently said to any passing human_ \- could always make his hearts feel like they’d fallen out of rhythm. When Pinstripes had said it, Saxon had almost cried, but that’d been a long, hungry day. He let the weight of his body drop heavily over her and tucked her head under his chin. He didn’t want to look at her while she looked at O like this. _You’re so pathetic, Doctor, it’s infuriating._ He pressed his face into the pillow beneath her.

He’d dragged this out too long. _This was meant to be fun._ He was meant to be O. He started to rock against her again, pressing his pelvis bone down hard so he was grinding against her clit. He could feel her heels digging sharply into his lower back, guiding him into a faster, more urgent pace. Her breath was a series of hot puffs against his torso. Her fingers curled up into his chest hair, tugging a little too tightly at the roots, exactly how he liked.

As he squeezed his arms tighter around her smaller frame, a tiny almost imperceptible sound caught his attention. What he’d thought were gasps and moans were actually near silent words that she was mouthing into his skin; soft breathes imperceptible to human ears.

He strained to decipher the movement of her lips as she arched under him. _Miss this, miss you. Missy?_ He would’ve fallen out of rhythm without her hips rocking him along. _She’s thinking about Missy. She’s thinking about me._ A warm feeling simmered inside him. It was probably his orgasm. He probably should’ve felt alarmed by her murmuring but O’s limited human hearing wouldn’t have heard her. Anyway, the heat in the pit of his stomach was growing. He was definitely close. He slammed into her again and again until her head had dropped back again her pillow and her soft murmurs trailed off once again into low moans.

She was clenching around him now. He could feel her body pulsing hungrily, grasping him tighter as she squeezed. His heartbeat was racing and he could feel the faint sheen of sweat between them as he thrust faster and harder into her. She reached down between their bodies to press urgent fingers against her clit.

It was too much. The way her eyes were so dilated, the way she felt so wet and hot, the way she threw her head back when her orgasm hit. He couldn’t help himself. He sank his teeth into her, clamping down on her bare neck as he came with a muffled shout. _Like an animal killing its prey. Beautiful._

________________________________________________________

When he opened his eyes again, he found himself lying on his stomach, panting softly into one of his pillows. The Doctor was lying on her side next to him with her head propped up on one arm. Her other hand was on his lower back, unbothered by the sweat cooling on his skin. She’d been staring at him, waiting for him to pay attention to her.

Her hair was a mess and the last bite he'd left on her was already bruising beautifully. _She'll be feeling that for days._

He knew he was smiling broadly in a way that would be fine for a homicidal maniac, and was probably also fine for a freshly fucked MI6 analyst but the look in her eyes made him pause.

“About what just happened," the Doctor’s face was scrunched up again, "Was it me or did you mansplain the female orgasm to a Time Lady?”

 _Excuse me? I upgraded first._ The Master was simultaneously relieved and flummoxed. He knew O looked gormless too. Too dazed by post-orgasmic bliss to know whether O would stutter into an apology or back himself with some vague reference to data and research, he settled for the best response he could think of.

“Did it work?” He was unimpressed when she burst into giggles. _Not cute, Doctor._

“I was only teasing,” she said, “Never took you for such a sexpert, is all."

He almost bristled before he remembered that he wasn't really O, that O had already sweet-talked her into his bed and that there were still clever ways in which the Master could hurt her, “You’re not the first blonde I’ve had in my bed.” 

“Oh?” her face was a lovely, moody picture. _Not so special, are you,_ _Sulking Storm?_

“Yes?” he hummed cheerfully. _You’re going to hurt yourself and I don’t even have to try._ He pulled her closer and swirled his tongue inside her ear.

She squirmed away restlessly, “No, I meant, oh, I didn’t know you liked blondes.” Her nose was crinkled. She was evidently annoyed.

“Isn’t it obvious?” he tugged gently on a loose strand, “You’re literally bottle-blonde.”

The Doctor blinked at him, “So I am. I forgot about that.”

She lay her head back down on the pillow beside him. The Master waited for her to soften against him before he jabbed.

“My late wife Lucy was a blonde.” He felt almost gleeful when she stiffened. _Wait until you realise it's me._

“What was she like?” the Doctor asked, her face was impassive and unreadable.

 _Generally obedient, totally unhinged, a surprisingly good shot at the end._ The Master let a genuine smile spread across O’s face. He really had been quite fond of Lucy Saxon and he could always appreciate a little hot-blooded vengeance. _My pets are so much better than yours. I always did have good taste._

“She looked fantastic in a red dress,” O replied.

“I’ve never worn one. They don’t look much good for running,” the Doctor grumbled. She was obviously jealous that O wasn’t completely in love with her; it was delightful. _But this will be more painful if you think he could be._ He reached over to pull her leg over his own.

“You look better wearing nothing at all,” O grinned at her, “but I’ve got something else planned for you, if you don’t mind?”

For a split-second, the Master could’ve sworn she looked uneasy but when he blinked, the Doctor was smiling again.

“What’s that, then?” she said.

“Dinner,” O said, “I don’t know much about Time Lord biology but it’s 10pm and humans need to eat.”

**Notes for the Chapter:**

> Was the Doctor really saying Missy or is that the Master's wishful thinking?


	5. Doctor's POV

O’s kitchen was more of a glorified pantry, so while he fussed around with double cream and eggs, the Doctor hovered awkwardly in the doorway. She’d offered to help but O had sweetly replied that she was his guest. Normally, she’d have said something insistently cheerful about being a team but she was well aware that the Master simply hated her cooking. _There’s nothing wrong with streaky-bacon-and-custard. Granted, it’s not my favourite -and-custard combo but you can’t seriously think the MI6 staff canteen does a better job._

“Is carbonara alright?” O asked, “I would’ve picked up something more exciting if I’d known you were coming.”

“Is carbonara alright? I eat carbonara for breakfast!” she grinned at O weakly, “I’ll eat anything, me. Unless it’s a pear. Not a fan of pears.”

Thankfully, the Master didn’t seem to pick up on her unease since O only smiled back warmly before turning to the cooker. While the Master seemed perfectly happy to keep playing O, the Doctor had a wibbly-wobbly sensation growing in the pit of her stomach. It was probably her Time senses warning her that she was risking a universe-ending paradox by being here. She was sure she would’ve hit him by now if she could. At the very least, she wanted to smack the bacon packet out of O’s lying hands. _Why are you only kind when you don’t mean it?_

 _It was also the nap’s fault_ , the Doctor reflected. _Naps are tricksy creatures. You should never trust something so self-indulgent._ She’d woken up feeling almost a thousand years younger and then the Master had been so disarmingly gentle. It had been the opposite of their first time at the Academy.

Then, he’d been terrified. First he’d prevaricated, saying he wanted it to be special and they should wait for a double lunar eclipse. When that had come round, he’d decided a triple lunar eclipse would be more fitting. Eventually, he’d hidden his fears behind indifference and bravado. When he’d finally agreed, she’d pounced on him with all her usual curiosity and enthusiasm. In hindsight, he’d only caved in to please her.

Over the years since, they’d done it every way. Every position wrapped up in every feeling. _Sorry-I-trapped-you-in-a-black-hole sex. You-deserved-to-fall-off-that-tower sex. Bite-me-with-your-Cheetah-teeth sex. Did-you-miss-me-when-I-was-dead sex. Let-me-out-of-this-cage sex. I-want-a-bigger-vault sex. Won’t-you-be-good sex. Admit-we’re-the-same sex._

Even as he pretended to be O, sex with the Master was like it always was; he’d been completely focused on her as he had been throughout all their lives. Whether he wanted to please her, punish her or deny her, he always took the time to learn her body first. He knew when to give, he knew when to take. _You always wanted to be like a god._

What had unsettled her was when O had asked if she was sure. In all their first times in all their new bodies, the Master always asked. Saxon had whipped her first and Missy had tied her to the grand piano but still, they’d asked in their own brutal way. Even if they would’ve punished her fiercely if she had refused. Sweet human O certainly didn’t need to be so gentle with a Time Lady fifty times his age. _How much of that was O? How much of that was you?_

The way O had brought up Lucy afterwards had been a low blow but it was just like the Master to be petty. Of course he’d plant hurtful seeds that she’d mull over later. As if she could be jealous over some human wife who hadn’t been even half as magnificent as River. No, what had annoyed her was how cavalier he had been. How many blonde women in red dresses called Lucy did he think there were? _You’ll ruin your own reveal if you aren’t careful._

Sighing inwardly, the Doctor cast a cursory glance over the kitchen. _Remember why you’re here. Why did he destroy our home?_ Disappointingly, the magnolia paint and pale grey countertop screamed ordinary instead of autocrat. A row of cupboards lined one wall but O had already dipped into most of them as he cooked and the Doctor had only caught a glimpse of boring things like spices and cookbooks.

She looked back at O. He’d put on a fresh white t-shirt and loose-fitting grey jogging bottoms while the Doctor had reclaimed her rainbow t-shirt and trousers from his bedroom floor. As he drained a pot of freshly cooked pasta into a colander, it struck her that this was possibly the most domesticated setting she and the Master had ever been in and as a bonus, one of them wasn’t holding the other captive. It didn’t make her feel better. _You should be travelling the stars with me. You could’ve stayed in the vault with me. You were meant to spend a thousand years -_

“All done,” O held up two mountainous bowls of pasta.

Still feeling gloomy, the Doctor followed O back into the living room. There was a small, square table pushed up against the window and two chairs facing each other under it. O dropped gracelessly into one and waved at her to make herself comfortable opposite him.

While she was still fiddling with the parmesan grater, O wolfed down his dinner with inhuman fervour, clearly too hungry to bother with conversation. The Doctor hid a wince behind the cheese mountain she was building. The Master was always like this, no matter how skinny his regenerations. There had been that unnerving time Saxon had hungered constantly for meat, uncaring if it was human or chicken, as long as it was roasted. And Missy’s takeaway bill had been the equivalent of several smaller planets’ GDP.

 _No wonder you were always wearing corsets_ , the Doctor thought uncharitably. The image he’d projected earlier of Missy dragging a nail along her skin still stung. Even though it had been imaginary, the Doctor felt certain that if she looked, she’d find some inexplicable red line seared across her chest. _So you’re after Missy. Whatever the Timeless Child is, you didn’t know it then. The vault was real._

When she looked up, O was eyeing up her own barely touched pasta. With a start, she realised the Master was probably still ravenous. For a moment, she considered whether he’d be more likely to let slip about the Timeless Child if he was hangry but something about his large, brown eyes made her soften. _Oh, go on then, you did do all the work I s’pose._

“You should have mine. I’m more of a dessert person,” the Doctor said. She almost laughed at the sight of O struggling to be polite until she took pity. The emergency biscuits she pulled from her trouser pocket were all the encouragement the Master needed. He reached for her bowl and inhaled the rest.

As she nibbled on a chocolate digestive, the Doctor turned the situation around in her head. She’d thought this all before but the same questions were even more baffling now the Master was in front of her. _Why did you say you'd arranged for me to die in the Kasavin’s realm, when you clearly hadn’t?_ His posturing had made sense at the time but later, between Paris and the holos, it all fell apart.

If there was one thing the Master enjoyed, it was a good gloat so _why go to the trouble of a geo-locked holo if I might not have seen it? Why drop half-clues about half-truths?_ Either he hadn’t really meant for her to die or he’d always known she’d get away. _But you’re the one who always escapes, not me. I’ll run out of regenerations long before you run out of ways to cheat death._

A sudden heavy clunk on the table jerked her away from her mounting misery.

“You look like you needed a cuppa,” O had cleared the pasta bowls and there were now two mugs and an assortment of biscuits between them.

“Sorry,” the Doctor said sheepishly, “I got lost inside my head.”

“Anything interesting up there?” O offered her a custard cream to go with the perfect tea-and-two-sugars he’d made her. _Plenty but none of it makes sense._

“Not really,” she pulled the biscuit apart carefully. O was stirring milk into his tea with a troubled frown. Hoping the Master would drop it if she didn’t say anymore, the Doctor busied herself with licking at the layer of thick cream until it melted under her tongue. When he finally spoke, it was a turn she wasn’t expecting.

“Do you regret what we did?” O asked, “Is it because I’m human?”

“What?” the Doctor gaped, “No, I was thinking about... someone else.” She trailed off lamely with a wince. _Well done, it’s not like he’s a possessive, self-obsessed lunatic or anything. You carry on._

“I see,” O looked even more upset now. _I was thinking about you and you’re pretending to be someone else, you murdering hypocrite._ The thought of hitting him crossed her mind again.

Openly pouting now, O bit into the heart of a Jammie Dodger with alarming fervour. The raspberry jam gleamed on his white teeth before a sip of tea washed it away. The Doctor racked her brains for the most plausible excuse to give him.

“I meant, I was thinking about my late wife,” she continued at last, “You mentioned Lucy earlier. It got me thinking about River, that’s all. Technically, she was human too so no, I’ve got no regrets.”

O nodded seriously at that, as if she’d said something profoundly interesting although she was sure she hadn’t. Then he opened his mouth and it fell into place.

“Do you date a lot of Earth girls?” he said. His tone was curious, instead of snide but the Doctor could’ve sworn the Master’s sneering criticism was ringing in her mind if not her ears.

“You’re my first Earth boy,” the Doctor replied evasively, knowing it would placate and irritate the Master in equal measure.

“We humans must seem so small to you,” O said, “Do you prefer us to your own kind?”

The Doctor pushed down a giggle. _Trust you to be jealous of yourself._ She dipped another custard cream into her tea and chewed slowly as she considered how to respond. _Should I tell O that he’s special? Or will the Master rage?_

“Humans are wondrous; they’re like fireworks. They shine so brightly but their lives are so short. I can’t take my eyes off them because they’re gone in a Time Lord’s heartbeat.” Out of habit, she tapped her mug with her nail. _Da-da-da-da. Da-da-da-da._

O’s gaze snapped sharply to her fingers before his expression smoothed into genial curiosity, “Is that- do you have two hearts?”

“Two hearts,” the Doctor nodded, “Four beats by two hearts.”

She stared into her mug, suddenly feeling warm and uncomfortable. She’d never say this to the Master; he’d probably throttle her before she could get the words out. But this was O so his response had to be kind, the Master had no choice.

“It’s different with a Time Lord. You give up one of your hearts for all your lifetimes. It doesn’t matter how far apart you are in space and time, there’s always a part of you waiting for them. Hoping for them.” She risked a glance upwards at O, “I’ve only ever loved one Time Lord. Actually, Lady. She was a Time Lady, last time I saw her.”

“What happened?” O asked, all innocence.

“She left me. Betrayed me actually,” the Doctor redirected her glare into her mug. An errant custard cream was dissolving at the bottom.

“She must’ve had good reason,” O said softly.

“Like what?” the Doctor scoffed, surprised by the sudden bitterness she could feel welling in her throat. _Go on, give me something. What have you ever cared about more than self-preservation? If you won’t tell me why you burned our home, at least give me this._ “What reason could she have had?”

“I couldn’t possibly tell you,” O’s hand was soft on hers, easing the mug out of her hand.

The evasion made her unbearably angry, “Is that all you have to say?”

O’s mouth was twisted into an infuriating parody of sympathy, “Does heartbreak hurt twice as much when you have two hearts?”

Her eyes were starting to prickle. _Don’t cry. He’s loving this. Your pain, your attention, your rage. It’s all he’s ever wanted._

“No. It doesn’t. It means I loved her twice as much and I forgave her twice as hard.” the Doctor was smiling widely now, knowing her words must be riling the Master, “I loved Missy because she could be so much more-”

“Painful,” O cut her off, “All that yearning sounds painful. No wonder you spend so much time with humans.”

“You’re right, O. It’s so much lovelier being here with you,” the Doctor smirked coolly as the Master’s face fell.

_______________________________________

It only took the Doctor eating three more custard creams before the guilt set it. _Never be cruel and never be cowardly, and if you ever are, always make amends._

The Doctor sighed. O was in the kitchen washing up. It was only the slightly louder than necessary clang of steel pots being thrown around in the sink that betrayed that the Master was in a massive sulk.

Tiptoeing to the kitchen, she watched O silently as he moved. Only the Master could make washing dishes look as peaceful as slaughtering rabbits. He was obviously furious and she’d better do something about it. _I’m only risking a paradox if the Master snaps._ She wrapped her arms around O’s waist and hugged him tightly from behind.

“You’re right,” she pressed her cheekbone into his shoulder blade. The tap was a gushing roar.

“I wasn’t aware I was ever wrong,” O replied.

“You weren’t,” the Doctor sighed against his back, “Missy once said we were infinitely complex. She meant it as a compliment but sometimes, it was the rage and pain of a thousand dying suns.”

O was still sloshing the mugs around in the soapy water but at least he’d stopped chucking them around like ceramic boulders.

“I’m not angry because she left,” the Doctor continued, squeezing herself against the heat of his back. She couldn’t hear his heartbeats over the noise of the tap, “I’m angry because the last time I saw her, her past self was there too and yes, it hurt twice as much.”

There was a sudden silence as O turned off the tap. She could feel his rib cage expanding and contracting within the circle of her arms. It disturbed her that she couldn’t feel his pulse through his t-shirt either.

Tucking her face into the back of his neck, she inhaled deeply. His musk reminded her of flames. _Our first kiss by candlelight. The first time we saw a sun die. The burning embers of Gallifrey._

She breathed into his skin, “One day he’ll do something unforgivable and I’ll still be here. Hoping for him.” The pause was long enough for her to worry. _Did he notice I switched pronouns?_

Suddenly, O turned round to wrap his own arms around her, “I might not be your Time Lord, Doctor, but I’m here now.”

She kissed him soundly.

_Da-da-da-da. Da-da-da-da. Da-da-da-da._


	6. Master's POV

When the Doctor kissed O in the kitchen, she’d kindled a wondrous sensation deep in the Master’s hearts and now, he couldn’t help but savour the pure joy thrumming through his body. Her miserable confession in the kitchen had been as glorious as the Gallifreyans’ dying cries. _Twice the pain. Twice the heartache and all because of me. It’s even better than the time I died in your arms._

He would’ve giggled if O’s lips weren’t pressed tightly against the Doctor’s neck. They were back in the living room, but now, they were curled up together on the sofa. The Doctor had squeezed herself sweetly against him, with both arms slung around his neck. This regeneration was needy and desperate for affection, constantly drawing O’s lips back to her own.

It was fortunate for the Doctor that for once the Master was willing to indulge her. O’s hands tangled into her hair tugging her head back gently, as the Master’s eyes roved over her exposed neck. Now that he had satisfied his curiosity over the Doctor’s new body, he wanted to drink in the damage he’d done earlier, while she was still so soft and unaware.

The bite marks on the Doctor’s neck had bloomed beautifully. While O peppered boring, tender kisses from her cheek down to her collarbone, the Master carefully catalogued his work. The first bite had been swift and borne from a sudden spike of frustration when she’d struggled to orgasm. Although he’d broken her skin, the indentations were shallow and would be gone by morning.

The second bite, however, was a work of art. By then, she’d been keening and mewling under him and really, _I just couldn’t help myself._ The imprint of his teeth were bloody trenches carved into her pale flesh. _That will hurt for days. Branded by your Master for all to see._ The two rows of tooth marks were surrounded by clouds of purple. He’d already favoured the colour in his last regeneration but this particular shade was especially pleasing. _I wonder what this bruise would look like on a suit? I could wear your pain like a trophy._

He marvelled at how blissfully oblivious the Doctor was. Even as he poked the tip of O’s tongue into the deepest cut, the Doctor only arched into him with another soft sigh. It reminded him of that time in Naismith’s mansion. The Doctor had been so smug when Saxon hadn’t noticed that the helmeted guard beside him was an inch taller than he should’ve been. How she’d jeered at him for missing the obvious. _Now look who’s ‘bone-dead stupid’, Doctor._

Once the Master was satisfied he’d committed her bruises to memory, he moved his mouth back to her lips. At least it was easy to keep her silent while he mulled over O’s next move. For the first time in all their lives, he wanted to encourage more of her incessant chatter. Especially after her strange emoting in the kitchen about his past selves. _How to pry without arousing suspicion?_

He could barely remember what had happened on the Mondasian ship. _Why would Saxon being there hurt more than Missy leaving?_ Even he would admit that that particular regeneration had been excessively unhinged. _I’m finally free from those infernal drums and you preferred the lunatic all along? My dear Doctor, I always knew you liked fixing me more than you liked me fixed._

At last, O pulled away from her kisses with a regretful sigh, “Doctor, I want to apologise for earlier. Just because I’m a spy doesn’t mean I should ask so many questions.”

“You should,” her eyes lit up with a forgiving smile, exactly as the Master expected, “I like talking to you. We’re friends, aren’t we?”

O nodded thoughtfully. _Are we? You don’t know who I am and you don’t even know yourself._ The Master let O bite his lower lip shyly before he replied, “I do have one more question, if I may?”

“Anything,” her palms were warm, cradled gently in O’s grip. They were soft and smooth, unlike his own. _If only you knew what these hands have done. The blood they’ve spilled. The necks they’ve wrung._

“You don’t have to answer, of course,” the Master made O’s eyes wide with human curiosity, “But when you said earlier that your Time Lady’s past self was there, how does that work? Was it alien?”

The Doctor snorted, “Everything’s alien to humans.”

O only beamed eagerly, “Was it technology? Biology?”

She sighed, “Both, I guess. When you can travel in space and time, it’s inevitable you bump into your past along the way. It’s dangerous too. If you’re not careful, you could tear the fabric of the universe apart. Create an unsustainable paradox. Wreak havoc on the known universe.”

 _I know. I did. You were there! Such a shame we can’t reminisce, love._ The Doctor was scowling at her hands now, undoubtedly recalling the Year-That-Never-Was. _We had some fun, didn’t we?_

“Only an idiot would do something so risky,” the Doctor finished numbly.

 _Only an idiot wouldn’t grasp the opportunity._ The Master hid his sneer behind O's commiserating wince, “Is that what happened? Did her two selves change something?”

“No, I don’t think so,” the Doctor was suddenly, unexpectedly fierce, “Missy would’ve left eventually, just not so soon. She was on my side that day. She said I was a sausage and she had a knife.” The Doctor’s hands had curled around each of his wrists in a loose circle.

O blinked slowly. _I threatened to slice you up? Kinky, but plausible._ To fill the silence, the Master leaned forward to press O’s lips against the furrowed line in the Doctor’s forehead, relishing the misery that was once again seeping off her brow.

“It was her past self,” her nails now dug painfully into O’s arms, sure to leave angry crescent moons on his skin, “The last time I saw him, we were on the same side. Then suddenly he was back and he was against me.”

The Master said nothing, thoughtfully scanning her face as he waited. Would her ramblings make more sense if he could remember better? _Probably not._ He could vaguely recall leaving her. There’d been some whining human refugees and then there’d been a way out for himselves. It was hardly remarkable he’d decided to literally abandon ship. _At least Loony version and Lady version said goodbye. Not that you appreciated it._

That was the one moment he could remember clearly. The Doctor had launched into one of her boring lectures on decency and kindness, as if that would ever interest him enough to stay. He remembered being Saxon and how the Doctor had stared straight at him, appealing to his nonexistent better nature like she always did. _Lame_. He remembered being Missy, watching the Doctor pleading with Saxon and wondering why he got the grand speech instead of her.

“He was against you?” O echoed gently, “Why would anyone be against you, Doctor?”

“He wasn’t at first,” her fingers tightened into shackles around his wrists, “But something changed when we were children. Someone tortured him.”

The Doctor was talking to herself now, as if she’d forgotten he was there. O only had to nod when she paused and look understanding when she stopped. It was old news anyway.

She continued, “He was only a child when our people put a drumbeat inside his mind. It tormented him for all his lives. He told me it was a call to war, but I didn’t listen. The more it changed him, the more I doubted him.”

If she wasn’t staring at his wrists, O’s hands would’ve clenched into fists. _You didn’t believe what they’d done to me. You’d never believe what they’ve done to you._

“It got worse,” she said with a grimace, “They said he was diseased. Albeit one of their own making. Those were their exact words and I still couldn’t kill him.”

She was talking about Naismith’s mansion, the Master realised. That time he’d opened the gate to bring the Time Lords home. It had been one of the rare, thrilling moments the Doctor had deigned to wield a gun. That hearts-stopping way she’d spun between him and Rassilon in turn when he’d goaded her to shoot. For the briefest of seconds he’d thought she might actually do it.

“Kill your friend?” O frowned at her. _But you never would, you coward. The link to Gallifrey was inside my head and even then you couldn’t do it._ “Did you want to?”

“No,” the Doctor’s eyes were confusingly grief-stricken, “It was Rassilon. Even when I knew what his High Council had done. They experimented on my oldest friend and tossed him aside. As if he wasn’t a child they’d tortured for their own gain. As if he wasn’t one of their own.”

O was silent. _That’s what they do, Doctor. Everything they did; everything I am. Our whole race was a disease of their own making._

The Doctor was whispering almost imperceptibly, with her eyes fixed on her hands held his, “I had the pistol in my hand. Rassilon was right there but I couldn’t do it. I sent him back into the pocket universe instead,” She glanced up at O uncertainly, “Do you know what a pocket universe is?”

 _That’s the bit of your nonsense you think a human couldn’t follow?_ The Master fought back a snarl. _If this is how you explain things, y_ _our pets must think Daleks are giant tea pots and Cybermen are upgraded Teletubbies._

When it finally came, O’s answer was tentative and charmingly simple, “Is it a universe trapped inside a pocket?”

“That’s right,” the Doctor nodded emphatically, obviously impressed by how clever O was. _You imbecile, it’s more of a bubble than a pocket. Planets can fall out of pockets, especially ones as disorganised as yours._

“And then?” O nudged. _How is this remotely relevant?_

“Then he did what I couldn’t. He followed them through the link to Gallifrey. The next time I saw Rassilon, he had a new regeneration. He’d taken his revenge,” the Doctor’s judgement reverberated in the space between them. _It wasn’t revenge. It was justice. I took it because you wouldn’t. I did what you never could._

“And?” O was prying again but his voice was still gentle and coaxing.

Her reply sounded lifetimes away, “That was the last time I saw him in that body. Facing Gallifrey together. That was the last time we were on the same side. Him and me, like we used to be and when Missy turned up later, she wanted to be my friend again. It’s all I’ve ever wanted.” _That’s what I wanted too. I didn’t know any better._

“And?” O’s tone was curt and brittle but the Doctor didn’t seem to notice.

“And I knew Missy. I knew that she was trying, even if she was leaving me. But he was exactly the same. The drums were gone and I thought without them, he might’ve changed. Just a little,” the Doctor's mouth was crumpled up strangely, “I thought it was me and him against Gallifrey but he left me again. We’d never been on the same side.”

“I need a minute,” the Master wrenched O’s hands out of her grasp. If he didn’t leave now, she’d realise O wasn’t real. _Nothing’s real. They ruined it. I thought we were the same and it was a lie. Our entire lives meant nothing._

_______________________________________

The harsh, white lights of the bathroom were a welcome sting in the Master’s eyes. He'd slammed the door behind him, shutting out the soft, dim glow of the living room he’d run from. She hadn’t followed him but her words had. _We’d never been on the same side._

Despite the cool of the porcelain sink under his palms, rings of heat still lingered from where her fingers had been wrapped around his wrists. They felt like ghostly manacles, marking out his crimes. Y _ou’ve always behaved like you were better. Where were your morals when it was me? Twice they changed my destiny. Twice I was their puppet. I don’t know what my life would be without their meddling. I don’t know what our lives might have been._

When he looked up into the bathroom mirror, O’s face twisted back at him in an anguished snarl. _If I hadn’t killed them already, I’d do it now. And I’d do it again because you still wouldn’t._ The only sound he could hear was his own fierce, shallow breaths. _I’m everything you‘ll never be and you never see it._ The Doctor was probably still curled up on the sofa, waiting for her pitiful human to return. Sitting in blissful ignorance of what the Time Lords had done to them both.

_Why aren’t you out there trying to find me? Why are you here with O?_

Scowling into the mirror at his stupid, floppy hair and his ugly, human clothes, the Master exhaled sharply and shattered O’s reflection with a single, furious punch.

_You never see me._


	7. Doctor's POV

The sound of something shattering rang in the Doctor’s ears like a thousand TARDIS alarm bells and of course, she was instantly up and running after the Master in a heedless panic. _Like I always am when you do something destructive and stupid._ She huffed bitterly as the doorknob jammed under her frantic, useless twists.

“O?” she rapped tentatively on the bathroom door. Her knocks were met with silence. _I shouldn’t chase him. I could make myself more tea? What did he say in Paris about wanting my attention?_

It took her a minute to realise that the Master wasn’t going to unlock the door. It took her another minute to remember her sonic screwdriver was in her coat, which was still on O’s bedroom floor. The sight of his rumpled bedsheets made her freeze for a third, even longer, minute. Suddenly, she felt tired in a way she hadn’t been since her last face. _For once, no-one’s going to die if I let him rage. I could go back to bed._

She sighed resignedly to herself. As if she could ever leave him in there. He was meant to be O; O was meant to be the Doctor’s friend and the Doctor wouldn’t leave her friend hurting and alone. _Not this time._

The door clicked open with a brisk wave of the sonic screwdriver. Inside, the Master sat on the edge of the bathtub, cradling his right arm with his left hand. Thin rivulets of blood trickled from his knuckles down towards his fingertips and onto the white tiles beneath.

“Everything alright?” the Doctor said, “I heard a crash.”

The Master was staring sullenly at the floor. She followed his gaze down to the shards of glass by his bare feet. He’d obviously punched - she glanced around - the mirror. _Of course you did._

“O?” she tried again, “Did you slip?”

“Did I slip?” the Master’s voice cracked in disbelief, “No, Doctor, I didn’t slip.”

There was a pause long enough for the Doctor to wonder if this was the calm before the paradox, but then the Master rubbed his uninjured hand over his mouth and with a bitter laugh, O was back.

“I’m not sure what happened. The room was spinning and I felt like I was going to faint,” O chuckled dryly but at least this time the sound was softer, “I think I actually might have. I woke up slumped over the sink and it was already like this.” He gestured vaguely at the floor with his bloody hand.

 _You’re brilliant, you really are_ \- she tiptoed over the glass shards towards him - _but that was awful. You can lie so much better than that. I’ve seen you._

Perching herself next to him on the rim of the bathtub, the Doctor reached out gingerly to grasp his wrist. Despite the blood, the wounds looked superficial enough. A human might have needed stitches but the cuts were already clotting on their own. Still, she ought to check if they were clean. Before she could scan his knuckles, O smoothly turned his hand over and wrapped his bloodstained fingers over the end of her screwdriver.

“Is that an alien medical device?” O said, “How very interesting.”

“It’s more of multipurpose thingy. I just want to see if there’s any glass...” the Doctor trailed off. _Any glass in your Time Lord body._ She lowered her arm slowly, “Mind if I take a look actually? I’ve got brilliant eyesight, me. Sonic screwdrivers aren’t what they used to be. I had a friend who preferred laser.”

She was rambling again and she knew it, but at least the sonic was back in her pocket and O had let her pull his bloodied fingers right up to the tip of her nose.

“Laser technology isn’t as powerful as one might think,” O said tersely, “Bit overhyped if you ask me and it’s got an unexpectedly high failure rate.”

The Doctor frowned into his hand. _Is that a clue about the Timeless Child or are you finally done bragging about laser? Because I remember how smug you were about upgrading your umbrella._

“But it’s always good to defy expectations, don’t you think?” O continued flatly, before wriggling his fingers under her nose, “Doctor?”

“Yes, all good. Looks very nice,” the Doctor felt herself flushing nervously. _You’ll be healed by morning and then I’ll really be caught. You’ll be caught. We’ll both be caught._

O was looking at her silently. He wasn’t his usual self but he wasn’t his actual self either. He was unnervingly in-between and in a bid to avoid his gaze, the Doctor fumbled desperately for a diversion.

“I don’t suppose you’ve got any - aha!” she grinned in relief as she caught a flash of green under the sink, “Throw us that bag and I’ll have you fixed up in no time.”

O stared at her for a long second before turning to grab the First Aid kit, “Fixed up?”

“Yea, you’ll see,” she flashed O a weak smile, “I’m surprised you’ve got this. You like to think ahead, don’t you?”

“It came with the flat,” O grunted, “MI6 sorted everything when I started.”

 _When the real O started._ The Doctor suppressed a shudder, recalling how the Master had carelessly tossed the miniaturised human aside on Barton’s aeroplane. _He’s probably here somewhere and I can’t help._ She frowned down at the medical kit in her lap.

As she flicked through the assorted shapes and sizes of plasters, she couldn’t help but glance sideways at the Master while he was too busy scowling at the floor to notice. He was drawing circles with his foot. Where his toes caught on the drying spots of blood, he left curved lines tracking along the tiles. It looked a little like her name if she tilted her head and ignored the fact that most of it was missing. _Now who’s a delusional madman? Madwoman._

“Pass me your hand?” she said, holding up a bottle of antiseptic.

His eyes flicked briefly towards her and before dropping his gaze back to his toes, “If you insist.”

He turned towards her and dropped his arm heavily onto the First Aid kit in her lap. To her relief, he didn’t object when she dabbed the antiseptic onto his cuts, aside from the slight, involuntary sniff he made when she pressed the cotton onto a deeper graze. _You did that in Paris. That little nose twitch. Like a deranged bunny._

He was getting careless with O. Either he was too angry to pay attention to the finer details anymore or he thought he had her completely fooled. It was probably the latter. _You always get careless when your plans are going well._

The Doctor sighed inwardly. Whatever the reason that had caused O to lash out, the Master must’ve been furious in the first place. _Something I said must’ve hit a nerve._ As she fiddled with a roll of tape and gauze, she cast her mind back to earlier in the living room.

She’d been dredging up their past encounters deliberately, hoping to provoke something about why he’d razed their home to the ground. _You were meant to say something revealing, not smash a mirror. Is this what testosterone looks like now I’m a woman? Cos I’m not impressed and Missy wouldn’t be either._

Gently, she started to wrap the bandage around the Master’s grazed knuckles. These weren’t the hands that had forced White Point Stars down Rassilon’s throat until he’d regenerated, but they were the ones that had massacred their entire species. That escalation had been irking her since she’d first seen what he’d done to their home. _What could be worst than what Rassilon and the High Council did to you? They literally tortured you over all your lifetimes._

She wanted to keep picking at O for answers but the Master’s reaction had hardly been helpful. She cast her mind back to the living room and the moment before O had fled. _What was I saying?_ She’d been on about Saxon following Gallifrey through the link and how from there, she’d thought they’d been against Rassilon together. _Why didn’t you come to me? I might’ve understood._

She had seen first-hand how the Master’s hunger for domination had ebbed once he was free of the drums. Missy wasn’t good exactly but she was certainly better. Eventually, she’d only killed people for amusement or opportunity or sometimes out of spite; not much more than that. Nuking their home wasn’t a game; it was vengeance and the Master had told her that himself. _You said you had to make them pay, but for what?_

She’d replayed his holo message over and over until every minute detail had singed into her brains; how the timbre of his voice had cracked and deepened, how his nostrils had flared and those wide eyes howled at her with something she couldn’t decipher. _You said it wasn’t easy but I could’ve helped. We could’ve found another way._

She glanced at him from the corner of her eye. _But you wouldn’t have liked that._ Perched beside her, O’s expression was stern and forbidding. She could almost picture how his face would contort into a withering sneer if the Master could hear her now. Only O’s messy, dorky hair and ill-fitting t-shirt would ruin the look.

O’s hand was bandaged up nicely now but she didn’t want to give it back to him yet. The silence felt like a brief moment of respite between the Master punching the mirror and whatever he would do next. _All this because of the Timeless Child, but Timeless Child who? You said that we’re not who we think we are. Does that mean it’s you?_

The Doctor turned back to the sullen figure beside her. If oblique memories weren’t going to prompt something useful, she’d have to be more direct.

“Did you feel anything before you blacked out?” the Doctor said brazenly, “Like someone else was in control?”

O frowned at her quizzically, “Are you asking if I’ve been possessed by an alien? Does that actually happen?”

“Yeah, I’ve seen it a few times!” the Doctor lit up with a smile, despite herself, “There was a parasite thing in Sheffield last year. Or maybe it’ll be next year. It looked like an octopus.”

“I’ll look out for it,” O nodded carefully, “But I don’t think I’m possessed right now. I certainly feel like I’m the O you know.”

She blinked at him. _The O I know doesn’t punch inanimate objects. Although he does trap aliens in metal cages..._ On reflection, it was obvious that O had been the Master all along. _O just shows off more discreetly._

“I know you’re O,” she cradled his bandaged hand between her own, “And you’re brilliant. But I thought, if you blacked out it could be something serious. Losing time like that could leave you...”

 _Timeless?_ She could feel her own nose scrunching up. _Where is that sentence going? Let’s try again. He hasn’t left me the holo yet so..._

“Let’s say you didn’t faint. That there was another person inside of you trying to get out and that was their moment,” said the Doctor, “Like everything you knew about yourself suddenly changed. What would you think?”

“I think it sounds like quite the adventure, Doctor. Your travels in space must be far more interesting than my days in MI6,” O replied breezily.

His deflection seemed a little obvious, especially for the Master. It took a second for the Doctor to catch up. _Oh I see, it sounds like I’m suggesting you’re a human secret agent possessed by a Time Lord with anger issues._

O continued with the diversion, “There is a small part of me that occasionally wants to kill C but I probably won’t. Not while he’s still got me on the payroll at least.”

His carefree answer was at odds with how flat and unamused his tone was. Point taken. _Direct questions aren’t going to get me where I want to be. Guess that’s why I’m the Doctor, not the Detective. Though I’d look quite fetching in a deerstalker._

“What about you?” O parried back smoothly, “Have you ever been someone else? Aside from the regenerating thing.”

She was about to say no when the Family of Blood sprang to mind. She could still feel Joan Redfern’s simmering condemnation when the schoolteacher had realised that the Doctor had brought such needless death to their doorstep. To Joan, John Smith had given up everything for the whims of a heartless Time Lord. _I did say he was still buried somewhere inside me._

“Only once, when I was still a man,” the Doctor said finally, “I hid my Time Lord mind inside a watch and my body became human.”

“What was that like?” O probed briskly, even though the Master already knew all about John Smith and Joan Redfern’s burgeoning, failed romance. When the Doctor had accidentally disappeared on Missy for six months, she’d been furious and bored and bitter. The Doctor had had to make up for it by recounting all the adventures that’d ended in misery and heartbreak.

It’d been maudlin and mean and the very opposite of what the Doctor wanted, which was why Missy had dug and twisted under the guise of curiosity. _Ugh, O’s exactly like you. He’s your own evil twin. Good twin._ The urge to hit him was back again, swelling in her hearts.

“He had his own thoughts and feelings. He even fell in love with a human woman,” the Doctor replied curtly, shoving O’s bandaged hand back at him with more force than either of them had been expecting.

“And how did you feel, Doctor? Did you love her back?” O hissed, his lips drawn back over gritted teeth in a pained grimace, “Even when you remembered who you were?”

She fought down the wild instinct to hiss back. _You mean did I love her the way I loved you? Why do you always test me?_

“No, I didn't. Once I had my memories back, he was buried too far inside me. But I would’ve tried. I even asked her to travel with me,” she choked back a hollow laugh. _Good thing she didn’t take me up on that. Imagine if she’d met you as Prime Minister. Joan would never have forgiven me for how I forgave you._

“And she didn’t want to?” asked O carefully, “To see the stars with you?”

The Doctor scowled down at O’s murdering hands, clenching and unclenching on his knees. _You didn’t either._ She had to force each bitter word out, “He wasn’t the same man anymore. Not the one she fell in love with.”

She could still picture their last conversation perfectly. The way Joan had stood by her cottage window in her quaint, buttoned-up dress and primly pinned bun and wondered so knowingly, ‘What must I look like to you? I must seem so very small.’

“And what about her?” O’s eyes were cold again, “Did she seem small to you?”

 _What?_ The Doctor poked frantically at her telepathic shields but they were as intact as they’d been since she’d first arrived. O was still watching her with those careful, wide eyes, waiting for an answer that she couldn’t breathe enough to give.

 _Calm down, Doctor._ She exhaled shakily. _The Master always thinks humans are tiny compared to us. Perfectly normal for him to sneak in some anti-human jibes while he’s a pretend-human. He’s probably laughing inside._

“Doctor?” O’s voice held the slightest note of impatience, “I asked if she seemed small to you, once you remembered who you were?”

“Yes, humans always do,” the Doctor mumbled finally, “And I’d only been him for three months, give or take. That’s nothing to a Time Lord.” _Nothing compared to the lifetimes we've spent fighting._

Unable to bear this pointless, meandering misery any longer, the Doctor turned to tidy away the mess of plasters she’d left scattered on the floor. _Come on, Detective brains, think._ Just as she squished the last plaster back into the First Aid Kit, a jar of hair gel and a purple comb caught her eye. _Aha, maybe there’s an indirect way of getting you to tell me about the Timeless Child._

Although O’s expression remained dark, he let the Doctor pull his chin towards her. She could feel the Master’s anger pulsing, just beyond the perimeter of her shields but the fuzziness of it was reassuring, especially as her hands were now raking through his scalp.

O didn’t object when she dipped her fingers into the jar or when she started swooshing his hair back and forth with the comb. She didn’t really know what she was doing but the gel was a nice, not-too-sticky texture that seemed to hold his hair where she wanted it.

She swept his hair across so it parted sharply on the opposite side to how O kept it, and then carefully combed his fringe so it hung dourly over his left eyebrow. Her hand drifted down thoughtfully to O’s clean shaven jaw. If only she could speed up his facial hair, he’d look more like her best enemy and it’d be easier to remember to hate him.

“There,” she said as she finally smoothed the last few, loose strands of hair into place, “What do you think?”

She held up the largest shard from the broken mirror that she could find. O’s face was thoughtful as he stared grimly into his own reflection. _Come on, Master, are you the Timeless Child?_

“I look like a different person,” O’s voice cracked, “Like you were, Doctor, when you hid your memories to play human.”

 _Useless. I’m not the only one with the human fixation, you obsessive hypocrite._ She dropped the glass shard into the bath tub in disgust, glaring as it shattered even more.

When she looked up again, O had risen to his feet. He was towering over her with an unreadable glower on his face. Although his eyes were steely and cold, his hand was warm and soft against her cheek. The Doctor gulped. This O-Master hybrid was unnerving and he was being even more unpredictable than usual; her better judgement was telling her to cut this off but it was hard to think when O’s hand was wrapped around her throat.

“Is that what you want, Doctor?” O’s eyes bore into her. He squeezed lightly and tilted her head up towards him. _What’s he playing at?_

“What?” the Doctor’s hearts were racing. His anger was still a fuzzy out-of-reach sensation in her mind. _There's no way he knows. There'd be Reapers._ Tentatively, she wrapped her hands around his wrist. His grip was firm but far gentler than it had been in Paris. There were at least fifteen different ways she could break his arm from this position and the Master knew it. _That’s it. He’s only playing._

“Call me by my name, Doctor,” O’s voice was cool and steady. He’d stop if she asked, she was sure of it.

“O,” the Doctor replied, loosening her grip around his wrist as he tightened his own around her neck. _So predictable._

“Beg your pardon?” he grinned darkly.

“Sir?” she rasped. _Okay, not that predictable._

“Can’t hear you, love,” his smirk grew wider.

 _He can’t mean-_ The Doctor would’ve laughed if that wouldn’t have ended in her actually being choked. _Totally predictable._

Her eyes met his hungry gaze, “Master.”


	8. Master's POV

“Master,” the Doctor’s voice was barely perceptible, yet his name seemed louder than the drums ever had. As the Master tightened his grip around her throat, her eyes only widened under his gaze. She was looking up at him with all the fear and recognition he’d been longing for.

Waves of relief swept through him. He’d always loved wringing his name from the Doctor’s unwilling lips. From the time when they were boys, on the day that he’d first chosen it, to all the lifetimes that’d followed, her mouth would curl into a mocking sneer or wrap each reluctant syllable with a furious hiss. Her anger could always set his hearts alight.

It hadn’t been the same in his last regeneration. He’d enjoyed playing with the disingenuous sweetness of being called Missy, but after all those years in the vault, it was a joy to hear the Doctor say the title he’d first picked once again. _Even if it's far too soon._ All his years of planning and the half-formed reveal he’d been so looking forward to, and with his short fuse, he’d blown that all to pieces.

The Master stared down at her. He wasn’t squeezing hard enough for her respiratory bypass to kick in and so, her mouth was goldfishing beautifully as she gasped each breath with little chokes that made him shiver. _Since I’ve ruined it, I might as well make the most of this mess._

He dragged her upwards by the neck. When she stumbled over the broken glass that was still scattered across the bathroom floor, he only shoved at her harder, until they were back in O’s living room and she was on her knees before him, slack-jawed and whimpering exquisitely around his cock.

“Hush now,” he purred as he rocked into her mouth, “Silence for your Master.”

She was doing a marvellous job of suppressing her gag reflex, considering her new body’s inexperience. Some of the Doctor's previous regenerations had needed far more practice. _It’s almost a shame you’re so good at this._ He would’ve enjoyed making her eyes water as he broke her in. Instead, they were wide-eyed to the point of awestruck.

He scowled. There was something in her gaze that was starting to grate. In that brief moment that he’d snapped, he’d been certain she’d seen who he was but suddenly, once again surrounded by the paraphernalia of his human disguise, he wasn’t so sure.

It wasn’t that he wanted to fight her exactly, but this wasn’t how he’d have pictured the Doctor reacting to his return. She still would’ve let the Master fuck her face like this, but she should’ve fumed about O first. At the very least, he’d have thought there’d be more dramatic recoiling-in-horror. _Then again, I wasn’t exactly thinking._

The whole situation was a step he hadn’t meant to take. O was supposed to be giving and vanilla; the Master had never considered that the Doctor would play along if the human went further. He’d lost his grip on the disguise there, he’d readily admit. _But you were being so annoying. Can I really blame me?_

He quickened the rocking of his hips with a heavy grunt. At first, it’d been the Doctor’s insufferable hero complex and how she’d fussed over O’s insignificant wounds as if he actually mattered. The Master would’ve shaken her off if the bandages wouldn’t come in useful for hiding his undamaged skin later. _You've already healed me and you don’t even know how you did it._

After that, her endless, posturing nonsense about her broken hearts only riled him further. _If any of that were true, you’d be out there looking for me, not seducing humans with your sob stories. And you wouldn’t let them seduce you either._ He thrust deeper into her mouth.

The tipping point had been when she’d started prattling on stupidly about Time Lord lifespans and her meaningless human dalliances. _All those precious moments with your little pets. It’s all a lie._ His rage flared and with some effort, he forced the thought aside to focus on the task at hand; shoving his cock as far down the Doctor’s throat as he could, over and over again.

The spectacular rush he’d felt when he’d thought the Doctor might’ve finally - _for once in your halfwitted lives_ \- actually seen him, had faded now into uncertainty. He’d fully expected her to fall cunt first for the human - he had custom-made O for her, after all - but he’d never have foreseen how keenly she’d leaned into him when O had towered menacingly over her.

 _Do you know it’s me or was that my wishful thinking?_ Or perhaps, with all that whining and moping she’d been doing over his past selves, it’d been hers. _Do you want him to be me?_

He slowed his movements and eventually, pulled out a little, giving the Doctor space to work her tongue against the underside of his cock. Her eyelids fluttered shut as she sucked wetly and he couldn’t help the soft sigh that escaped him. At least that was a sound that a lovestruck human would make, so he wasn’t too concerned.

“Good girl,” he breathed, careful to add the slightest caress into O’s voice. It wouldn’t do to ruin something so dangerously indulgent by reminding her too sharply of himself. Not when it had felt so good to pretend that she was seeing him for who he was, instead of the pitiful, simpering human he was pretending to be.

The adrenaline had drained out of him and he could feel disappointment growing where he knew he ought to be feeling relief. _At least I haven’t spoiled my own reveal. If anything, that was a fine rehearsal. Plenty to work with for next time. I have notes._

As he’d pushed her towards saying his name, it’d felt like all the planets he’d ever burned were simmering together in his hearts. _We’ll do that again but better. I’ll even run the same lines._ He suppressed a giggle. She’d hate saying his name once she knew who he was but she’d have no choice. _I’ll make sure of it. No hands-on-necks next time. Something more fun. Perhaps I’ll threaten a passing stray._

The more innocent the human, the more unwillingly she’d bend. _And isn’t that a fun idea?_ Next time, he wouldn’t let her sit comfortably, like she’d been on the edge of O’s bathtub. _I’ll make you kneel._ Like she was kneeling now with his cock in her mouth. _My name on your lips, you at my feet. What a perfect echo of O and how it’ll sting._

He was getting harder at the thought, if that was even possible. The Doctor was always so much more interesting when he pushed all her buttons and he could almost picture the fury in her eyes. Almost because right now, they were distractingly soft, staring up at O with such compliant adoration.

 _Boring._ With his bandaged right hand, he yanked her hair back sharply. The resulting hiss of pain and the sharp scratch of her teeth as she winced around his cock was exquisite but it wasn’t enough to calm the rage he could feel brewing again.

If anything, it was even more infuriating that she was still gazing so saccharinely at O. The Master started to pound into her mouth again, harder and faster and deeper than before. Her eyes were finally starting to water and she was making those delicious, gagging sounds that he hadn’t heard since the Doctor wore pinstripes but still, even her face was becoming annoying. _He’s not your Master, I am._

He pulled out and shoved her sharply onto her back, “Strip.”

“What?” she stuttered, hands shaking as she fumbled with her braces. Her chin was shining with spit and her face were flushed and sweaty. _You’re a mess. A stupid, irritating mess._

“You’re trying my patience,” he pulled her t-shirt off impatiently, “Turn over.”

She didn’t move. Instead, she shivered and wrapped her arms around her naked chest. He would’ve enjoyed the sight except-

“O?” she gulped.

With a growl, he dropped down onto his knees to face her. They weren’t exactly eye-level but they were close enough that he could grab her by the chin and tug her up towards him. The trepidation he’d seen in the bathroom was back.

“No, love,” he tempered O’s voice into something flat but commanding, “Now turn over.”

The sudden glimmer of resistance in her eyes was thrilling. It was a long moment before she obeyed and it was only when she was on her hands and knees, facing away from him, that he allowed a smirk to spread across O’s face.

From there, it was easy to strip the rest of her clothes off himself. It was an added bonus to see her flailing on the floor as he dragged her trousers off her and then, she was completely naked on all fours.

He leaned forward to grab her hair and wrench her head backwards. From that angle, she couldn’t meet his eyes, even with her back completely arched, but he still had a perfect view of her wincing at the ceiling. _Glorious._

“Come on, Doctor,” he growled, “You know what I want.”

Grabbing his erection, he nudged her knees apart. As he traced her opening with her head of his cock, he could feel her pressing backwards eagerly. She was already soaking.

“Say it,” he could feel pre-cum weeping from his erection, mixing with her wetness as he dragged his cock from her entrance to her labia and back again.

Her reply was wrapped up in a heated gasp, “Please.”

“What’s that, love?” he said, teasing his cock against her, just enough to feel the ring of her muscle grasping hungrily at the tip. His rage had disappeared, now that he could feel her thighs trembling lightly against his own. _I can wait all day._

There was a long moment of silence but he wasn’t concerned. He rocked patiently against her, relishing the heat of her slickness against him. _Come on, Doctor, say it, say it._

“Master,” she finally spat out, her whole body now quivering under the strain, “Please, Master.”

He sunk into her with a sigh. _You only had to ask, love._

He didn’t wait for her to adjust. As far as he was concerned, O’s seduction and her first time with him had already been accomplished. _Now your Master gets to play._ In any case, he didn’t actually have to do anything other than keep his left hand tangled tightly into her hair and hold himself steady as she slammed her hips backwards onto his cock.

As she snapped back and forth with sharp, needy jolts, swaying on her elbows, he could feel her inner walls clenching and fluttering around him. With his free hand, he reached round so that his fingers brushed against her clit as she rocked. Soon, she was panting heavily, alternately slamming herself backwards and then grinding downwards into the hand pressed into her pubic bone.

Her movements were focused and intentional, but every time he sensed her nearing her release, the Master would shift his fingers minutely, either circling ever-so-slightly too far from her clit or dancing downwards to rub at her swollen labia.

Soon, she was grunting with the slightest edge of frustration that made his hearts feel especially gleeful. Beads of sweat were making their way from the nape of her neck, down her back and pooling at the base of her spine.

It wasn’t long before he could feel his balls tightening from her increasingly frantic flexing and squeezing around his cock but he wasn’t ready for it to be over yet. He dropped his hands onto her hips and with a snarl, shoved her forward roughly so that she face-planted onto the floor with a shocked cry.

Leaning forward onto his left hand, he dropped his weight onto the bookcase in front of her so that she was trapped beneath him. _Exactly where you should be._ Stabilising himself against the shelves, it only took a few, deep, steady thrusts before she was whimpering into O’s carpet.

 _So different in this body but still the same._ With his right hand, he tugged at her hips, nudging them upwards until a sudden wail erupted from her. Triumphant, he sped up his thrusts, pounding into her relentlessly.

He’d fucked her like this a thousand times before, hitting that spot inside her that always made her squeal, even when she had a male regeneration. Before, her erection would drip pre-cum onto her ground beneath her belly and the Master would shove her into it. He’d make her slide and stick against her own fluids, rubbing herself against the floor for relief because he wouldn’t touch her or let her touch herself. _We've had some fun, didn’t we? So why stop now?_

He slammed into her gleefully. Her thighs were wet with her slick and his sweat and soon, he was grunting with exertion in time with her moans. Whenever she summoned up enough desperate energy to wriggle a hand towards her clit, he’d knock it away with a roar. It wasn’t long before she gave up and was a helpless, whimpering mess, wailing muffled cries into the floor. _Exactly as you should be, Doctor._

But there was something about her moans that were beginning to unsettle him. The Master slowed down his rhythm, slamming into her more deliberately than before. Blocking out the sensation of her warmth and wetness around his cock, he focused on each grunt she made as he snapped into her. The louder she got, the more obvious it was that she wasn’t simply crying out in wordless pleasure. _Why are you saying that stupid human’s name?_

His rage was refuelled and his right hand slammed down on her backside as he roared, “Say. My. Name."

He struck her over and over again. Under his palm, her pale skin flushed a deep red. O would probably have checked she wanted this, but the Master didn’t care and anyway, he knew the Doctor better than any human ever would. _Better than you know yourself._

By the time he stopped, she was chanting his name into the carpet and his fury had finally subsided enough to hear it. He dug his fingers into her rear, watching as his nails left half-moons in her tender flesh, and waited.

“Master,” she mumbled finally, “Please, Master, please.”

But he was still too enraged, even though she was begging so nicely. He tightened his grip on her hips and started rocking into her once again. This time, however, he was careful to keep his movements shallow and angle himself away from the sweet spot inside her. _I hope you’re suffering comfortably, Doctor._

Her irritated huffs and futile wriggling were a balm to his anger and finally, he relented. It only took him one, deep, considered thrust to hit his mark.

“Master,” she wailed in relief.

“Yes,” he snarled, finally feeling content enough to resume pounding into her. She’d given up holding herself up and now her hands were curled up in awkward, little fists beneath her face. But despite the beating, her cries soon subsided back those little wordless pants that sounded too much like that idiot's name.

“No, not him. My name. Mine,” he panted roughly. He was being careless and he knew it. O’s magazines and tiny alien figurines were tumbling off the bookcase in a shower of human rubbish that only made the Master angrier. He reached forwards to pull the Doctor's head back towards him. Her blonde hair was sweaty under his grasp, but that only made him yank it tighter until her back was arched and her gaze fixed helplessly on the ceiling.

From this angle he could see her face and how her mouth hung open, as she huffed those irritating little ohs as he thrusted into her. It was apparent she was unaware of anything beyond the sensation of his cock inside her body. _Useless, stupid Doctor._

He growled. _Have it your way. I’ll take my pleasure and give you all the pain._ With one hand still tangled into her hair, the other slamming down hard on her right buttock, and his cock pounding into her relentlessly, the Doctor was exactly where he'd wanted her since he’d found her on O’s doorstep. There were even tear tracks trailing down her cheeks and the pitch of her wails was sensational... except that he still couldn’t overlook the way she was howling that stupid human’s name over and over.

With a sudden final sob, she orgasmed around him. He could feel her clenching brutally tight around his cock and he probably would have come too, only - _I’m your Master. There's only me._

He pulled out, too infuriated to continue. _Won’t you just shut up for once?_ He tugged at her shoulder and she flopped onto her back like a worn out, rag doll.

“Open wide,” he grunted, kneeling over her. He was about to shove his aching cock into her mouth, when the strange angle of her arm beside her head made him pause. There was something in her hand and even before he'd unfurled her fingers, he could feel his stomach sinking in a way that was familiar.

He’d felt the same sensation on the Valiant when the Doctor had tapped into the Archangel network. He’d felt it on the Mondasian ship when the Doctor had reprogrammed the definition of human to include two hearts. It was the same feeling he had now, staring down at the tiny, compressed O he’d been keeping, now curled up in the middle of the Doctor’s fist. _It must’ve fallen off the shelf. How long have you been holding him?_

He glanced sideways at her warily. Her eyes were wet and red and he couldn't tell what she was thinking or if it was too late. He opened his mouth unsure what, if anything, he could possibly say... but before he could speak, the Doctor let out a wild scream and the Master was falling backwards, with both her hands around his throat and the tiny O discarded on the ground between them.

**Notes for the Chapter:**

> Was the Doctor saying O or moaning ohhhh? Was she still trying to pretend he's O? Was the Master's insecurity and jealousy making him paranoid? Tell me what you think in the comments. There are no wrong answers.


	9. Doctor's POV

When the real O first plummeted from his spot, high up on the Master’s bookshelf, the Doctor didn’t see him. With the Master shoving her roughly, destructively, forward over and over, O’s paraphernalia of magazines and alien artefacts had been tumbling down and around her for a while, so when the tiny, compressed figure bounced off the back of her head and landed on the carpet by her panting face, the Doctor’s eyes had long slipped closed.

All her senses were redirected onto the strange-yet-familiar buzz of her new body and her new Master, and the dangerous thrill of chanting his name into the carpet while O fucked her from behind. It was a rush she didn’t know she’d needed; it was every reason why she shouldn’t be there - _but where would I be without you? Who would I be?_

By the time the Doctor was aware that something small and sharp was digging into her cheek, she couldn’t think whole words anymore, let alone say the Master’s name coherently, no matter how much he raged for it. Her knees had given out and she was shaking too much from her own need and his steady thrusts to hold herself up.

Even her breaths had reduced to shaky, little huffs forced out of her lungs by the Master slamming his cock precisely and relentlessly into her. Relief felt like a clifftop a thousand times further than when she’d been a man and the climb towards it was both glorious and agonising. All she could think was _please, Master_ and _more, Master_ and _why, Master?_

It was only the sudden weight of his palm striking her buttock without warning that made the Doctor’s eyes fly open in shock. And it was only when his hips stilled and the Master struck her again and again, that the sting of his hand called her mind back into the room and she finally realised that the tiny object stabbing into her cheek had a shape, and that shape was humanoid and -

“O!” she gasped.

Two small eyes and a frozen little face stared up her, unseeing and reproachful and _\- I’m sorry. I’m so sorry._

The Doctor had only caught a glimpse of the tiny compressed human in his matchbox before the Master had tossed him aside on Barton’s plane, and now, here he was, a shrunken tissue sample on the floor. She hadn’t known this human _\- the real O_. She’d never met him. She didn’t even know if she’d have liked him but still, he was dead. Murdered by the -

“Master,” the cry was wrenched from her throat as he suddenly, brutally slammed himself deep inside her once more.

“Yes,” the Master hissed gleefully as he started pounding into her again with the same meticulous aim he always had when he had a target in mind. The yearning inside her had been overwhelming before but now, with the real O staring up at her and the Master’s hands pinning her in place, each jab of his cock now stoked something that felt less like lust and more like Gallifrey burning all over again.

Unable to bear O’s lifeless gaze any longer, she curled her fingers over his tiny face, hiding him from view. She should move. She should leave _\- How can I be a good man when -_ but before she could push herself up, or consider how she’d even begin to go, the Master’s left hand had tangled into her hair and her spine was arched almost painfully backwards, until the Doctor couldn’t have moved even if she’d wanted to.

She could only gape upwards at the Master who was growling furious half-sentences at her that she couldn’t understand and suddenly, she wasn’t so sure about leaving after all. With the Master holding her in place, she couldn’t meet his eyes and even better, she couldn’t look down at the real O either. The miniaturised figure felt solid and inexplicably heavy in her clenched fist, but grief and shame felt different when all she could see was the Master’s hypnotic, wolfish snarl.

Suddenly, the hand in the Doctor’s hair twisted, sending sparks of pain running radiating along her scalp and the indecision over whether she was coming or going melted away as she sank into the pain with a cry of relief. While she didn’t have the strength to fight the pull of the tiny O, whose weight still dragged her downwards, she didn’t have to even try when the Master’s fierce grip kept her body arched up towards his own.

When he started hitting her again, it felt like a dam breaking within her hearts. The sting on her backside was sharp and distinctly unpleasant and yet, the pain filled her with warm, agonising relief. With each slam of his right palm on her bottom, ripples of anguish rolled over her and through her until there was nothing left but a thick layer of numb heat flowing through her as the Master thrust into her again and again and again.

It was like being propelled toward hellfire, but it was only when the Doctor’s orgasm hit, and wave after wave of hot, shameful bliss swept through her body, that she realised the Master hadn’t been pushing her towards the flames. He was merely on the other side, waiting amidst the smoke and she had leapt, willingly, to join him.

As the fizz of orgasmic aftershocks rumbled through her body, the Doctor slumped uselessly on the floor. She knew her cheeks were damp and she could feel her body trembling but they were only abstract sensations compared to the heaviness that now filled her limbs. She was only vaguely aware of the Master pulling his cock out of her and rolling her roughly onto her back. Suddenly, he was kneeling over her, a looming figure with his erection a giant swinging pendulum above her face

“Open wide,” he growled, but with the fog of need no longer clouding her brains, she couldn’t bear to look at him, any part of him. _What am I doing? Why I am here?_

Instinctively, her grip tightened around the compressed figure still in her hand _\- I have to keep O safe -_ but before she could roll them both away, the Master had lurched towards her fist and was carefully peeling her fingers, one by one, from around O’s tiny dead body.

He stared down at her palm for a long, cold minute, but that was all the Doctor needed. With the pretence of playing human long gone, the Master’s face was now a contortion of dangerous cunning and blistering pain. He looked exactly like he had on the Eiffel Tower, with his mouth twisting in false sorrow, even as he’d goaded her - _‘Our home, razed to the ground. Everyone killed. Everything burned’._

He’d looked so pained but it’d all been lies, like everything else about him. Grief swelled in the Doctor’s hearts again, but this time, it was followed by a hot, thick roar of anger at the Master and Missy and the Master again. _Why did you do it? When will you stop?_

When the Master finally turned to look at her, all she could see in his eyes was her own anger reflected back at her and with a burst of energy she didn’t know she had, the Doctor was flying upwards, her arms outstretched and the tiny O flung aside. Only one thought rang through her mind. _I have a right to know why._

Her hands were too small to throttle him properly and anyway, choking was his thing. This new body of hers preferred to shove and punch and beat, and soon, rage had overtaken her entirely. _Why did you kill them? Why did you leave me? Why did you lie?_

The Master wasn’t fighting back. In fact, he wasn’t moving at all. He’d tumbled back onto O’s floor in a soft heap and each time the Doctor’s fist landed on his chest, his only response was an infuriating cackle. Between his growing laughter and her flailing arms, it was so far into paradox-inducing that soon, the Doctor couldn’t tell if the screaming was her or him or if the Reapers were outside. _When will this end?_

It was only the sharp crack of the Master’s head smacking against the floor that stopped her breaking his nose entirely. Blood streamed down his chin from one nostril but she didn’t feel any remorse. Not when he was still making those long, deep chuckles that made the Doctor’s skin rankle. Every cell in her brains cried out at her to hit him again. _It’s always a game to you._

“What?” she snarled, “What’s so funny?”

“Oh, Doctor, really,” he grinned “I’m not telling you.”

This time, her feral scream was followed by a sharp knee into his groin, but his smirk only stretched wider. The pain must’ve been unbearable and yet, the Master’s eyes were bright with glee and he was panting hotly into her cheek.

“Yes, that’s it,” he hissed through gritted teeth, “Come on, Doctor.”

Despite his taunting leer, the Master’s body was tight with tension. She could feel him trembling as much as she was. His hands were down by her hips but instead of fighting her off or pulling her close, they simply hovered. Somehow, his restraint made her angrier. _No more games._

Moving swiftly, the Doctor pinned the Master’s wrists above his head. As she dug her nails into his skin, she sank her weight into him until her knee was a pinpoint of unrelenting pressure on his erection and he was hissing up at her through clenched teeth. _You said it hurt. The lie of the Timeless Child. Does it hurt as much as this? Does it hurt as much as I do?_

“Do it,” his lips burned against her skin, “Come on, come on, come on.”

His cock was weeping now and she could feel herself sliding over him, even as she pressed her shin against his balls. She wanted to smack the smirk off his face. She wanted to make him stop gloating up at her. She wanted him to hurt as much as she did, and yet, the more she dug her weight into his groin, the more he arched up against her.

His eyes were huge, watering orbs staring up into hers and she could see her own reflection swimming in his pupils. _Does the history between us mean anything to you?_

“Finish it,” he breathed and at last, she did.

She clamped her jaws onto his throat and bit down until smoke and ash flooded into her mouth. For a never-ending moment, the Master twitched and jerked beneath her, a wild, chaotic beast trapped between her teeth until hot, thick ropes of cum erupted into the space between their bodies.

When he finally stilled and sagged into the floor, the Doctor collapsed on top of him, panting into his neck. Blood trickled from her mouth and the wound she’d left behind, and she could feel his cum cooling on his stomach and her thigh, sealing them together.

For the first time since she’d seen Gallifrey razed to the ground, the Doctor felt completely drained. For once, the Master was quiet and yielding beneath her.

When she lifted her head to look up at him, the Master’s eyes were glazed and half shut. Bruises were already blooming over his skin, his nose was swelling and the remnants of a tear track shone on his cheek, within touching distance of her tongue. She hadn’t seen him cry since he’d been Missy. _The only person I’ve ever met who’s even remotely like me._

Pressing her forehead softly against his, the Doctor closed her eyes, letting the rasp of the Master’s shallow breaths and the rhythm of his double heartbeat wash over her. _The friend inside the enemy, the enemy inside the friend._ O had been her friend and the Doctor was here, pretending to be O’s.

_Was I your enemy all along?_

________________________________________________________

It was dark and quiet when the Doctor woke. She was lying under a hot, fluffy cloud and the ground beneath her was rumbling lightly. It took her a full minute to realise that she was back in O’s bedroom and under his duvet _\- far too comfortable not to be your actual duvet -_ and that the minor earthquake was actually the soft rise and fall of the Time Lord whose chest she was lying on. _Again._

The Master’s face was slack in sleep, without any lingering tension or expression. His eyelashes were far longer and prettier than hers. She hadn’t noticed when he was awake but now he couldn’t distract her with those huge, wavering eyes, she found herself gazing at them silently. _I wonder if he’s dreaming about the Timeless Child, whatever that is._

She was tempted to peek but - _that would definitely be too far. Or is it already too late?_ Glancing down at the Master’s torso and at his arms loosely clasped around her, she balked at the bruises staining his skin. They were dark red swirls that reminded her of the smoke plumes on Gallifrey, only this time she was the one who'd caused them. Dried blood had crusted over the bedsheets, under his face and neck. She’d beaten him and bitten him far worse than he had her.

Carefully, not yet wanting to wake him, she turned her head from side to side. The bites he’d left on her were tender but not particularly concerning. She flexed her toes slowly, feeling her legs stretch awake. He’d been brutal while spanking her, or so it’d felt at the time, but he’d still been deliberate and now, there wasn’t any hint of remaining soreness in her body. Unlike the Master, who’d be aching for days, judging by the swelling on his cheekbones alone.

The Doctor shut her eyes against his bruised, sleeping body. She’d come here looking for clues about the Timeless Child and instead, she’d only ended up hurting them both. _You said we were the same but perhaps I’m more. Perhaps I’m worse._

She stuck her tongue out to taste the time.

“It’s 8am."

She froze and flicked her gaze up towards him - _here comes the paradox_ \- but the Master's eyes were fixed on the alarm clock on the bedside table. His arms tightened around her just enough that she might’ve thought he was cuddling her, if she didn’t know better.

“We’d better get up soon,” he sighed, “C’s a stickler for his morning meetings.”

The Doctor blinked up at him. _Wait a minute. Are you still pretending to be O?_

“Unless you can drop me off at MI6 with your time machine?” His hands were drifting softly over her skin

She frowned into his chest hair. _And let you wreak havoc in my TARDIS? And what about the real O? You killed him and I hurt you._

“Best not,” the Doctor said after the briefest of pauses, “She’s not very reliable with short hops. I could end up jumping you into next week.”

“Never mind then,” He had a hand in her hair now, massaging her scalp softly. His gentle tone was in stark contrast to a few hours earlier. _Is this another one of your games? Are you going to leap up and shout ‘got you’?_

“About last night...” she trailed off, tensing for the fall-out that was surely coming... but O merely smiled at her, genially.

“That was nice, wasn’t it? Our little roleplay?” he said, “Isn't it fun to pretend to be someone else? You seemed to like it too. I didn't know you had so much rage inside you, Doctor. You're more like us humans that I thought.”

His hand had shifted from her hair down to her cheek, but his touch was still soft. She tucked her nose into his collarbone. _Have you really not realised I'm here from your future? Do you really think I'd call anyone else by your name?_ O’s aftershave had long faded and the Master’s familiar musk was there, underneath the scent of Earth detergents from the bedding. Familiar because after all this time, he really hadn't changed.

Her mind ran back to Naismith's mansion when the Master had missed the slightly taller soldier, and then to the graveyard when Missy hadn't spotted Danny Pink ignoring the orders she'd barked at the Cyber Army. And finally, on the Mondasian Ship, when the Doctor had slumped over the computer and changed the definition of human to include two hearts, all before the Master's eyes and still he hadn't suspected a thing. _You always want my attention but you never know when you've got it. Maybe if you stopped showing off, you might finally win._

“Did you?” O was tracing his thumb along her lower lip, “Did you like me being someone else?” _Is that it? You were so busy being you, you didn't look at me?_

“Yes,” she breathed into his neck, poking her tongue into the bite marks she’d made until he sniffed, “This time, yes.”

He was unbelievable... _but wasn’t he always?_ She probably should’ve been offended that the Master apparently thought her so gullible, but her overwhelming feeling was relief. _At least the timelines are intact and I can leave before I make it worse._

She pressed her little finger into the bruise swelling on his left cheek.

“Does it hurt?” she asked, wondering idly if regret would come later. _Didn't my outburst surprise you at all?_

“Yes, but it's all fun and games,” O hummed, before planting a cheerful kiss on her mouth, “You should’ve seen what my late wife Lucy did. She practically killed me once but I bounced right back.”

And with that, the Master stretched languidly and rolled out of bed, leaving the Doctor seething behind him. _Idiot._

________________________________________________________

While the Master showered, the Doctor dragged a comb through her hair, splashed her face and placed the tiny O back on the living room bookshelf. A part of her wanted to take him and bury him somewhere far away, but whatever absurd story the Master thought was playing out in the Doctor’s head would definitely be ruined if O went missing now.

As she waited for him to finish dressing, the Doctor half-heartedly snooped through O’s cupboards. Inevitably she didn’t find anything revealing and only felt grumpier as a result.

“Fancy a coffee from the high street?” O said, immaculate in his MI6 suit, as they left his flat.

The Doctor shook her head. Facing the Master in the bright morning light, almost exactly where he’d first caught her spying yesterday, the bruising on his face and neck looked worse than it had before. And yet, the more she gazed at the damage she’d done, the more she wished she’d broken his nose after all and the more she knew she should never have come. It wasn’t exactly regret but it wasn’t far from it either. _Can I still be a good person when I'm with you?_

“I can’t,” she said, “I've already stayed too long.”

O nodded understandingly, “There’s so much of the universe to see. I’m not surprised you’re always running somewhere new.”

The Doctor was silent. For the first time in a millennia, the compulsion to beg the Master to come with her wasn’t there. _Maybe if you’d change, I’d have nothing to run from._

“You’re welcome to visit anytime, Doctor,” O tangled his fingers into hers.

“I’ll text you,” she said and his smile disappeared.

“I see,” he said, “It’s like that.”

“No, it isn’t. I just...” the Doctor paused and squeezed his hand tightly, searching for the right words, “I don’t want to make promises I can’t keep. Not to you.” _I’ll skip forward to next week and call you. And I’ll do the same for next month. You’ll be texting me soon and then I’ll see you in Australia. It’s the safest thing to do._

Suddenly, O pulled her into a tight hug and murmured into her ear, “Don’t worry, Doctor. You have your adventures. I’ll keep my eye on you from MI6. After all, my whole life there revolves around you.”

It was an echo of Missy who'd said the exact opposite once. The Master probably meant to scare her or at the very least, leave her something to fret over in a year’s time, but the Doctor only clung back tighter. _I was right. Hugging is a great way to hide your face._ After all, she knew he was lying. His plans were with the Kasavin and his anger was with Gallifrey and the Timeless Child. _Nothing to do with me, not this time._

It was only when she pulled away that she realised she’d been squeezing him too hard. O’s friendly smile had twisted into a wince and his hand leapt up to cradle his ribs.

“Careful, Doctor,” O said ruefully, “I'm beginning to think you like hurting me.”

The Master's eyes were so wide, that she was half-tempted to agree and so, instead of saying anything, the Doctor pressed a silent kiss into his cheek and turned away.

_We’re not so different, you and me._

**Notes for the Chapter:**

> THE END! Whoop! I can't believe I've made it this far. I can't believe you've read this far!
> 
> So I feel I've pushed 'how far can our two idiots lie to themselves and each other' to the absolute limits here... Whether or not you think the Master had realised she's from his future or not, well....head over to Part 2 to find out!
> 
> Comments and kudos always welcome, even if you’re reading this in 2050... this was a labour of love so it would brighten my day to know you enjoyed it too.


End file.
